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  • 1. Battley, Mark
    et al.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Characterization of Ductile Core Materials2010In: Journal of Sandwich Structures and Materials, ISSN 1099-6362, E-ISSN 1530-7972, Vol. 12, no 2, p. 237-252Article in journal (Refereed)
    Abstract [en]

    This article describes an experimental investigation of characterization methods for ductile core materials. Full-field optical strain measurement methods are used to determine the strain distributions in standard testing methods such as block shear and four-point beam testing, particularly for highly ductile cores subjected to large deformations. The results show that the stress and strain fields in both block shear and sandwich beam tests are very different to those assumed by the testing standards. The test methods result in complex post yield states of stress in the core materials, meaning the core shear strength and ultimate shear strain should not be calculated by classical methods in the post yield region.

  • 2.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Composites in ships2010In: 1st conference on Service vessels for offshore wind park, 2010Conference paper (Other academic)
  • 3.
    Burman, Magnus
    KTH, Superseded Departments, Aeronautical Engineering.
    Fatigue crack initiation and propagation in sandwich structures1998Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    The focus throughout this thesis is on the fatigue characteristics of core materials used insandwich structures. Three sandwich configurations are investigated, two with cellular foamsand one with honeycomb core material These corresponds to typical materials and dimensionsused in the marine and aeronautical industry.A modified four-point bending rig, which enables reversed loading, is successfully used forconstant amplitude fatigue tests of all material configurations. The core materials are tested asused in composite sandwich beams and through the design of the specimens the desiredfailure is in shear of the core. Analyses and inspections during and after the tests supports thetheory that the fracture initiation and fatigue failure occurs in a large zone of the core withwell distributed micro cracks rather than a single propagating crack. The fatigue test resultsare plotted in stress life diagrams including a Weibull type function which provides a goodaccuracy curve fit to the results. The fatigue life of the core materials is found to be reducedwith a increased load ratio, R.The influence on the strength and fatigue performance on sandwich beams with two types ofcore damages, an interfacial disbond and a flawed butt-joint, are experimentally investigated.The fatigue failure initiates at the stress intensity locations which are present due to the predamage.The specimens with flawed butt-joints display a fatigue crack propagation in theinterface between the core and face of the sandwich while the crack propagates through thethickness of the beams where an initial interface flaw is present. A fatigue failure predictionmodel is suggested which utilises the fatigue performance of undamaged beams and thestrength reduction due to the damages. The approach is correlated with results from fatiguetesting and satisfactory correlation is found.A uni-axial fatigue tests method is developed which simplifies the rig and specimenscompared to the four point bend method. A comparison between the results from uni-axialtension/compression fatigue tests and shear fatigue tests shows good correlation, although theR-dependency differs in some cases.The fatigue crack propagation rates are investigated for two configurations: crackspropagating in pure foam core material and cracks propagating in the core material near andalong a sandwich face/core interface. The rate at which a crack propagates stable in the socalled Paris’ regime is extracted for both Mode I and Mode II loading. The agreement betweenthe Mode I crack propagation rate in the pure foam and in the core/face sandwich interfacelayer supports the theory that the crack actually propagates in the sandwich core beneath astiffened resin rich layer present in the face/core interface. The stress intensity thresholds andthe limits at which the crack growth becomes unstable are further established.Acoustic Emission (AE) is used to monitor crack initiation and growth in the core, duringboth static and fatigue loading. It is found that the approximate location of AE-hits can bedetermined which demonstrates that AE has a potential both as an non destructive testing tooland to study the failure process of non-visible sub-surface damages in sandwich structures.

  • 4.
    Burman, Magnus
    KTH, Superseded Departments, Aeronautical and Vehicle Engineering.
    Residual Shear Strength of Polymeric Foams after Fatigue Testing2003In: 6:th International Conference on Sandwich Structures (ICSS-6), / [ed] Vinson, Rajapakse and Carlsson, New York: CRC Press , 2003, p. 522-529Conference paper (Other academic)
  • 5.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Sandwich Materials in Buildings2005In: The 16th SICOMP Conference on Manufacturing and Design of Composites, 2005Conference paper (Other academic)
  • 6.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Colombo, C.
    Vergani, L.
    Static and fatigue characterisation of new basalt fibre reinforced composites2011In: 16th International Conference on Composite Structures, ICCS 16 / [ed] prof Antonio Ferreria, 2011Conference paper (Other academic)
  • 7.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Colombo, C.
    Vergani, L.
    Static and fatigue characterisation of new basalt fibre reinforced composites2012In: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 94, no 3, p. 165-1174Article in journal (Refereed)
    Abstract [en]

    Basalt reinforced composites are recently developed materials. These mineral amorphousfibres are a valid alternative to carbon fibres for their lower cost, and to glass fibres for their strength.In order to use basalt reinforced composites for structural applications, it is necessary to perform amechanical characterization. With this aim in the present work experimental results of several staticand fatigue tests are described. Two polymeric matrices are taken into account, vinylester and epoxy,to assess their influence on the evaluated parameters. In parallel to these mechanical tests, also thethermal answer of the specimens to mechanical loads is evaluated by means of thermography. Thisexperimental technique allows defining the composite local heating during the application ofmechanical loads and its behaviour in details. Final discussion on obtained results is proposedfocussing the attention on basalt fibre composite behaviour, and comparing mechanical properties ofBFRP with other composite materials in glass and carbon fibres.

  • 8.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Fernades, A. A.
    Ferreria, A.
    Cirrone, G.
    Adams, R.
    Araujo, F.
    Scamuzzi, M.
    Ruiz, J.
    Fernandes, F.
    Vicente, T.
    Salomon, O.
    Ziegmann, G.
    Mauri, U.
    Vergani, L.
    LITEBUS - Modular Lightweight Sandwich Bus Concept2008In: Transport Research Arena - TRA 2008, 2008Conference paper (Other academic)
  • 9.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Hedlund Åström, Anna
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Lingg, B.
    Villinger, S.
    Enlund, H.
    Hellbratt, S-E
    Cost and Energy Assessment of a High Speed Ship2008In: International Journal of Small Craft Technology, RINA - Part B, ISSN 1740-0694, Vol. 150, no 1, p. 1-10Article in journal (Refereed)
  • 10.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Kuttenkeuler, Jakob
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Comparative Life Cycle Assessment (LCA) of the Hull of a High Speed Craft2011In: 16th International Conference on Composite Structures / [ed] Prof Antonio Ferreria, 2011Conference paper (Other academic)
  • 11.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Kuttenkeuler, Jakob
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Comparative Life Cycle Assessment (LCA) of theHull of a High Speed CraftIn: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085Article in journal (Other academic)
    Abstract [en]

    A comparative Life Cycle Assessment (LCA) has been performed on the hull of a 24 meter long high speed patrol craft. The aim of the study is to compare different structural materials concepts to determine differences and sensitivities in environmental impact, especially in relation to the total impact including fuel burn. The material concepts studied are aluminium and various composite combinations consisting of glass fibre and carbon fibre with vinyl ester resin both as single skins and as sandwich with a Divinycell foam core. For each material concept a unique and weight optimized structural design was employed fulfilling the DNV high speed craft design code [1]. All identical systems and components for the five hull concepts are omitted in the LCA and hence a comparative study is performed focused on the hull structure. The commercial software SimaPro have been utilized for the LCA calculations and the impact assessment method chosen is the CML Baseline 2000.

    The structural optimization carried out in [1] show that a weight reduction by to up to 50% (on the hull) could be achieved by switching from aluminium to a carbon fibre sandwich concept. The weight reduction switching from glass fibre single skin to a carbon fibre sandwich concept is roughly 20%.

     

    The LCA study performed herein shows that, regardless of hull material concept, the environmental impact is by large dominated by the usage phase due to relatively large fuel consumption. A lower structural weight will reduce the fuel consumption and hence the environmental impact. This is illustrated in fig. 1 for the aluminum hull. All different phases of the life cycle are plotted for all environmental impact categories assessed herein. The green color is related to the operation phase and the red is the manufacturing phase. As observed the operation phase is dominating.

     

    In fig. 2 are the results from the LCA presented for all hull concepts and for all environmental impact factors. The Al-hull is the concept with highest structural weight (red bars) and hence was found to have the highest environmental impact. The carbon fibre sandwich hull (green bars) had the lowest weight of the five and consequently the lowest environmental impact.

    In the normalization analysis performed, in which different impact factors are assessed using a common impact unit, three impact factors stand out as dominating, independent of hull concept; Abiotic depletion, Global warming and Acidification. All these impact factors are herein associated with the usage phase and diesel consumption. If the operation phase is omitted and only the manufacturing phase (including the material extraction/manufacturing) is studied the observation is that the aluminium concept still will have the largest environmental impact for all categories. The most significant environmental impact is now on the marine and the fresh water aquatic ecotoxicity which is associated with the aluminium raw material excavation and manufacturing processes.

     

  • 12.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Kuttenkeuler, Jakob
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Stenius, Ivan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Garme, Karl
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Rosen, Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Comparative Life Cycle Assessment of the hull of a high-speed craft2016In: Journal of Engineering for the Maritime Environment (Part M), ISSN 1475-0902, E-ISSN 2041-3084, Vol. 230, no 2, p. 378-387Article in journal (Refereed)
    Abstract [en]

    A comparative Life Cycle Assessment is performed for different structural material concepts on a 24-m-long high-speed patrol craft. The study is comparative and determines the differences in and sensitivities to environmental impact, especially in relation to the total impact of fuel burn for the different material concepts. The material concepts are aluminium and various composite combinations consisting of glass fibre and carbon fibre with vinyl ester resin both as single skins and as sandwich with a Divinycell foam core. Commercially available standard Life Cycle Assessment software is used for the Life Cycle Assessment calculations. The study shows that regardless of hull material concept, the environmental impact is dominated by the operational phase due to relatively large fuel consumption. In the operational phase, the lightest carbon-fibre concept is shown to have least environmental impact. Considering the manufacturing phase exclusively for the different hull concepts, it is concluded that the manufacturing of the aluminium hull has a somewhat larger environment impact for the majority of Life Cycle Assessment impact categories in comparison to the different composite hulls. The significant impact on the marine and the fresh water aquatic ecotoxicity originates from the aluminium raw material excavation and manufacturing processes. It is shown that the lightest hull, the carbon-fibre sandwich concept, with a 50% structural weight reduction compared to the aluminium design, can be utilized to reduce the fuel consumption by 20% (775 ton of diesel) over the lifetime with significant impact on the dominating environmental aspects considered herein, abiotic depletion, global warming and acidification.

  • 13. Burman, Magnus
    et al.
    Lingg, B.
    Villinger, S.
    Enlund, H.
    Hedlund Åström, Anna
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Hellbratt, S-E
    Cost and energy assessment of a high speed ship2006In: Second Conference on High Performance Yacht Design, 2006Conference paper (Other academic)
    Abstract [en]

    A comparison in total life cycle costs and energy consumption for one high speed ship design with three different structural materials have been performed. The investigation considers a high speed ferry with a steel hull and an aluminium superstructure, an all aluminium concept and a ship built in sandwich material with carbon fibre faces. The different materials will affect several cost elements during the design, the production and the operation of the ship until and including its disposal. Furthermore, the material selection has an impact on the energy consumption within all stages of the ships life cycle. The assessment is made in a comparative manner. Hence, identical out fitting components, e.g. interior, instrumentation, and ventilation are left out. It is shown that the steel version causes the highest costs and energy consumption. The sandwich construction has the lowest life cycle costs while the aluminium version has the lowest energy consumption. The break-even point between the steel and the composite versions appears after 4 years (only 2 years of operation!), the break-even point between the aluminium and the composite ferry is after 12 years (10 years of operation). A sensitivity analysis with different possible scenarios, e.g. change in interest, petrol cost, maintenance cost, has been performed. All of the investigated scenarios identify the composite version to have the lowest life cycle costs. This paper summarises an original work carried out as a master of science work as given in [1-2].

  • 14.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Neves, P.
    Uni of Porto.
    Grimaldi, R.
    INSIA.
    Niemeyer, S.
    Univerity of Claustahl.
    Salomon, O.
    CIMNE.
    Ziegmann, G.
    Univerity of Claustahl.
    Ferreria, A.
    University of Porto.
    Fernandes, A.A.
    University of Porto.
    Bus Pillar Test Monitoring, Simulation and Validation2009In: 15th International Conference on Composite Structures, 2009Conference paper (Other academic)
  • 15.
    Burman, Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Rosén, Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Zenkert, Dan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Spectrum Slam Fatigue Loading of Sandwich Materials for Marine Structures2010Conference paper (Other academic)
    Abstract [en]

    Sandwich materials are more frequently used in high speed craft and ferries. The motivation is reduced weight and associated operational cost. The hull structure in these vessels is subjected to repeated (fatigue) slamming loads (high strain rate loading). Scantling societies treat sandwich materials differently in their design rules. In common reduction or safety factors on the static strength of sandwich materials are used calculating the design stress. In most rules there is no explicit consideration of fatigue performance nor of the altered material properties related to high strain rate loading. In this work actual response measurements on a high speed vessel are used to formulate a tentative slam fatigue loading spectrum for sandwich core materials. This spectrum is then used in the testing of one type of core material common in hulls panels, Divinycell H200. The slam spectrum fatigue results are then compared to fatigue test results based on constant amplitude loading based on a method of equivalent stress. Earlier studies indicate that slamming fatigue do not affect the life compared to constant amplitude loading. However there are also studies that indicate that both a static overload (post the yield point) prior to fatigue loading, and block sequence fatigue loadings with initial high amplitudes followed by low amplitude have a detrimental effect of the fatigue life. In the current study both various amplitudes and high strain rates are included in the fatigue loading sequence. The spectrum fatigue results match the fatigue life from the constant amplitude loading. However, the number of samples is limited and the different effects of fatigue at high strain rates and fatigue block sequence are not fully clarified. It is possible that those effects may counteract each other in the current work. Further studies on sandwich foam core material properties and improvement of methods for material characterization is concluded to be of interest and will follow.

  • 16.
    Kazemahvazi, Sohrab
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Zenkert, Dan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    NOTCH AND STRAIN RATE SENSITIVITY OF NON CRIMP FABRIC COMPOSITES2007In: ICCM16, 2007Conference paper (Other academic)
    Abstract [en]

    The notch and strain rate sensitivity of noncrimp glass fibre/vinyl-ester laminates subjected to uniaxial tensile loads has been investigated experimentally. Two set of notch configurations were tested; one where circular holes were drilled and another where fragment simulating projectiles were fired through the plate creating a notch. Experiments were conducted for strain rates ranging from 10-4/s to 102/s using servo hydraulic machines. A significant increase in strength with increasing strain rate was observed for both notched and unnotched specimens. High speed photography revealed changes in failure mode, for certain laminate configurations, as the strain rate increased. The tested laminate configurations showed fairly small notch sensitivity for the whole range of strain rates.

  • 17.
    Kazemahvazi, Sohrab
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Zenkert, Dan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Notch and Strain Rate Sensitivity of Non-Crimp Fabric Composites2009In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 69, no 6, p. 793-800Article in journal (Refereed)
    Abstract [en]

    The notch and strain rate sensitivity of noncrimp glass fibre/vinyl-ester laminates subjected to uniaxial tensile loads has been investigated experimentally. Two set of notch configurations were tested; one where circular holes were drilled and another where fragment simulating projectiles were fired through the plate creating a notch. Experiments were conducted for strain rates rangingfrom 10-4/s to 102/s using servo hydraulic machines. A significant increase in strength with increasing strain rate was observed for both notched and unnotched specimens. High speed photography revealed changes in failure mode, for certain laminate configurations, as the strain rate increased. The tested laminate configurations showed fairly small notch sensitivity for the whole range of strain rates.

  • 18.
    Ljungdahl, Jonas
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Berglund, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Transverse anisotropy of compressive failure in European oak: A digital speckle photography study2006In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 60, no 2, p. 190-195Article in journal (Refereed)
    Abstract [en]

    The mechanical behaviour of European oak (Quercus robur L.) was studied in radial and tangential compression. Young's modulus and the yield strength were approximately 1.7- and 1.6-fold higher, respectively, in the radial direction. Strain fields were determined by digital speckle photography (DSP). Strains and the effective Poisson ratio could be determined separately in earlywood and latewood during deformation and failure events. In radial compression, strain data showed that rays contributed significantly to the high modulus. In addition, multiseriate ray microbuckling was observed to control yield strength. The microbuckling was localised in the low- density earlywood. In tangential compression, yield strength was controlled by vessel collapse in the low- density regions of the latewood. The strain field data provide direct evidence that the rays are the main microstructural factor controlling transverse anisotropy in European oak.

  • 19.
    Rajput, Moeen S
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Hallström, Stefan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Distinguishing between Strain Measurement Procedures during Compressive Testing of Foam Materials2015In: Proceedings of the 20th International Conference on Composite Materials, INTERNATIONAL COMMITTEE ON COMPOSITE MATERIALS , 2015Conference paper (Other academic)
    Abstract [en]

    The out-of-plane compressive properties of foam materials are essential for their performance as core material in sandwich structures. Accurate data for these properties are crucial for modeling and analysis of impact response and critical design assessment of e.g. sandwich structures. Current standards differ in specifying how the strains should be measured. When different standard methods are used, significant differences in test results for flatwise compression are obtained. An experimental study of the out-of-plane compressive properties (strength and modulus) of foam materials is conducted, where two types of foams are studied; Rohacell 200 Hero and Divinycell H60. Both are closed cell structured foams used for cores in sandwich materials. A review of established test methodologies is conducted and the test results show that there is a significant difference in strain values measured from the cross head displacement (termed “gross core strain”) and when extensometer directly applied onto the foam (termed “net core strain”). The results are not related to the compliance of the test rig, which is another issue outside the scope of this investigation. The effect of surface priming on the compressive behavior is further investigated followed by digital image correlation (DIC) for detailed recordings of the strain fields.

  • 20.
    Rajput, Moeen S
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Köll, Joonas
    Hallström, Stefan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Compression of structural foam materials: Experimental and numerical assessment of test procedure and specimen size effects2017In: Journal of Sandwich Structures and Materials, ISSN 1099-6362, E-ISSN 1530-7972Article in journal (Refereed)
    Abstract [en]

    This study was initiated based on the observation that standardized test for flatwise compression of foam materials, give significantly different test results for the measured moduli, and that these standards to date lack adequate instructions on how the strain should be measured and what specimen size should be used. A brief review of previous work shows that existing test methodologies provide significantly different results for the compressive moduli of foams depending on how the strains are measured. A thorough experimental study of the out-of-plane compressive properties is conducted on three different closed-cell foam materials, where strains measured with two different extensometer placements, and with digital image correlation, come out significantly differently. A parametric study is also performed showing that the results vary considerably with in-plane specimen dimensions, indicating effects of finite size and localized strain at edges. Both stochastic amorphous and homogenized finite element models of foam back the experimental observations by illustrating the effects of finite size and various boundary conditions on the measured properties.

  • 21.
    Rajput, Moeen S.
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures. Odqvist Laboratory, KTH.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures. Odqvist Laboratory, KTH.
    Segalini, Antonio
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. Odqvist Laboratory, KTH.
    Hallström, Stefan
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures. Odqvist Laboratory, KTH.
    Design and evaluation of a novel instrumented drop-weight rig for controlled impact testing of polymer composites2018In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 68, p. 446-455Article in journal (Refereed)
    Abstract [en]

    A drop-weight rig (DWR) intended to test the true impact response of laminated compositematerials is presented. The test setup is designed to prevent the transfer of unwanted mechanical noise, e.g. vibrations, into the load cell that is used to measure the load during the impact event. A novel catch mechanism preventing secondary impact is also implemented in the DWR design. A detailed evaluation is performed both in terms of the experimental modal and uncertainty analysis of the measured results from the DWR. The results demonstrate that the rig is capable of capturing the true impact response, providing highly resolved and noise-free force-time measurements where even subtle details of the impact event are visible. The rig also enables impact testing with good repeatability.

  • 22.
    Rathanatavorn, Wallop
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Melander, Arne
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Welding Technology.
    Lindh-Ulmgren, Eva
    Swerea KIMAB.
    Åkermo, Malin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. mburman@kth.se.
    Hybrid joining of alumnium to thermoplastics with friction stir welding2012In: Proceedings Swedish production  Symposium 2012, 2012Conference paper (Refereed)
  • 23.
    Stenius, Ivan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Rosén, Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Kuttenkeuler, Jakob
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Norrby, Monica
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Razola, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Kompositfartyg - en kort introduktion2011Report (Other academic)
  • 24.
    Stenius, Ivan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Garme, Karl
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Hall Kihl, Susanna
    Vattenbussen AB.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Waterway 365: System Analysis of Challenges in Increased Urban Mobility by Utilization of the Water Ways2014Report (Other (popular science, discussion, etc.))
    Abstract [en]

    Effective transport solutions for goods and people are crucial for the economic development of a region or city. In major cities worldwide there is a lack of capacity in the road and rail network resulting in high costs, only in Stockholm the cost of the overall shortcomings of commuting has been estimated to 6.3 billion SEK annually. The current trend is further increased congestions in major existing commut- ing routes (roads, rail networks and metro networks).

    In coastal cities like Stockholm, Gothenburg or Copenhagen however, there are inland waterways that would enable shorter and faster commuting routes if efficient land-sea based transportation systems are implemented. In addition the waterway constitutes an opportunity to create new city space, add transport capacity, offer new communication paths, change the transport flow and level off the pres- sure on the present transport system.

    The waterways and parts of the road network are existing infrastructure resources that may be used to contribute to more sustainable travel patterns, reduce congestion on main commuting corridors, in- crease capacity and the traffic system's resilience through new travel relationships, travel patterns and synergies with bicycle and city logistics.

    The aim of this work is to identify the most relevant research topics and key performance parameters for personal transport and city logistics systems on the waterways in urban environments for year- round service. The long-term goal is to identify transport systems and technical solutions for the wa- terways that can be scaled and adapted to urban environments around the world and that complement the land-based transport systems in order to achieve an over-all sustainable urban mobility.

    This work focuses on a systems engineering perspective and includes identification of system bounda- ries and interfaces to other public transport, infrastructure nodes, system service and maintenance and measurement of sustainability and service improvement targets. The aim is to develop a base for a system that can be scaled and adapted to urban environments around the world - like how road or rail- based mass transit systems today are built up from more or less standard units, not to design a public transport solution for a specific city, route or line. The focus is on realistic solutions that are both achievable from a cost perspective and attractive to passengers during 365 days a year. New concepts, ranging from small single person commuters up to large public transport systems, are to be explored and evaluated and key technical challenges identified and targeted.

    The research initiative Waterway 365 was initiated by The Royal Institute of Technology (KTH) and Vattenbussen AB with support from the Swedish Maritime Administration (Proj. no: 15041-0). 

  • 25.
    Wallmark, Oskar
    et al.
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Malmquist, Daniel
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Wennhage, Per
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Géoren, Peter
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Design and implementation of an experimental research and concept demonstration vehicle2014In: 2014 IEEE Vehicle Power and Propulsion Conference, VPPC 2014, IEEE conference proceedings, 2014Conference paper (Refereed)
    Abstract [en]

    This paper introduces the Research Concept Vehicle (RCV), an experimental research and demonstration vehicle developed at KTH Royal Institute of Technology. The vehicle is intended as a platform to implement, validate, and demonstrate research results from different research projects carried out at KTH. In its first generation, the RCV is a pure electric vehicle where each wheel is equipped with an in-wheel motor and individual steering and camber actuators. This high level of over actuation allows for a wide range of experimental evaluation in several fields of research, which is listed in this paper. Results from initial experimental test drives are also included.

  • 26.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Failure mode shifts during constant amplitude fatigue loading of GFRP/foam core sandwich beams2011In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 33, no 2, p. 217-222Article in journal (Refereed)
    Abstract [en]

    This paper presents fatigue results for sandwich beams that exhibit a transition in failure mode, from core shear failure to face laminate tensile failure, as function of load amplitude only. The basis of this are fatigue tests of foam cores in shear and tensile tests on composite laminates. These results show that the slopes of the stress-life (S-N) relation are different for the core and laminates. By using the obtained stress-life relations, a simple design scheme is given for sandwich beams which are anticipated to have a transition of failure mode for a particular load level. Two designs are manufactured and tested in fatigue under constant amplitude loading. The results clearly show the aim of investigation with transitions in failure modes giving a structural stress-life diagram a bi-linear shape. For high load and small number of cycles to failure, the beams fail by core shear fracture while for lower loads, and large number of cycles to failure the beams fail by face sheet tensile failure.

  • 27.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Failure Mode Shifts in Fatigue of Sandwich Beams2009Conference paper (Other academic)
    Abstract [en]

    Sandwich beams are designed and tested in fatigue, and it is found that for high load and small number of cycles to failure, the beams fail by face tensile fracture. For lower loads, and large number of cycles to failure, the beams fail by core shear.

  • 28.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Fatigue of closed-cell foams in compression2011In: Journal of Sandwich Structures and Materials, ISSN 1099-6362, E-ISSN 1530-7972, Vol. 13, no 4, p. 467-478Article in journal (Refereed)
    Abstract [en]

    This article deals with fatigue of closed-cell foams under compression loading. Testing is performed on three densities of Divinycell H-grade and three densities of Rohacell WF-grade foam under cyclic compression loading. The fatigue failure is in all cases described as localized crushing of cell layers. The two main observations from this are that the slopes of the stress-life curves are almost all different, both between the foam types and relative density. Secondly, the stress-life relation slopes are considerably flatter than corresponding data in tension. For one particular foam grade, the stress-life relation is almost flat.

  • 29.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Tension, compression and shear fatigue of a closed cell foam2007In: 16th International Conference on Composite Materials, ICCM-16, 2007Conference paper (Refereed)
    Abstract [en]

    A closed cell foam of Polymetacrylimide (Rohacell) with three different densities is studied. The foam is tested quasistatically in tension, compression and shear. The tensile properties scale very well with the relative density of the foam, but the compression and shear properties do not. It is believed to be due to cell edge and cell wall buckling being the dominated deformation mechanism in compression and shear for lower densities that does not occur for higher densities. Fatigue testing is then performed in tension, compression and shear. It is seen that for all load cases and densities, the fatigue life can be plotted using Basquin's law. The results also show that the different failure mechanisms found in the static tests are the same in fatigue. This means that the fatigue life for different load types exhibit different failure mechanisms. This shows not only as a clear difference in the stress levels for fatigue failure, but also on the slope in the fatigue life relation.

  • 30.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Tension, compression and shear fatigue of a closed cell polymer foam2009In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, p. 785-792Article in journal (Refereed)
    Abstract [en]

    A closed cell foam of Polymetacrylimide (Rohacell) with three different densities is studied. The foam is tested quasistatically in tension, compression and shear. The tensile properties scale very well with the relative density of the foam, but the compression and shear properties do not. It is believed to be due to cell edge and cell wall buckling being the dominated deformation mechanism in compression and shear for lower densities that does not occur for higher densities. Fatigue testing is then performed in tension, compression and shear. It is seen that for all load cases and densities, the fatigue life can be plotted using Basquin’s law. The results also show that the different failure mechanisms found in the static tests are the same in fatigue. This means that the fatigue life for different load types exhibit different failure mechanisms. This shows not only as a clear difference in the stress levels for fatigue failure, but also on the slope in the fatigue life relation.

  • 31.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Kazemahvazi, Sohrab
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Fatigue of foam core sandwich beams under localized loads2011Conference paper (Other academic)
    Abstract [en]

    Sandwich structures offer significant weight savings in many structural applications due to their high stiffness and bending strength to weight ratios. However, one Achilles heal of sandwich structures is their poor capability to carry localized loads. In this paper we investigate the fatigue behavior of sandwich beams subjected to localised loads.

  • 32.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Kazemahvazi, Sohrab
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Fatigue of sandwich beams under localised loads2011In: ICCM International Conferences on Composite Materials, 2011Conference paper (Refereed)
  • 33.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Shipsha, Andrey
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Fatigue of closed cell foams2005In: Sandwich Structures7: Advancing with Sandwich Structures and Materials / [ed] Thomsen, OT; Bozhevolnaya, E; Lyckegaard, A, Springer Netherlands, 2005, p. 171-181Conference paper (Refereed)
    Abstract [en]

    This paper deals with fatigue of closed cell foams. The main idea is to use a few simple tests to predict the tension-tension fatigue properties of foams. The required testing consists of crack propagation rate measurements and one tension-tension fatigue test performed at yield stress for the foam. This data can then be combined to construct a synthetic S-N Curve for the foam. Tests on three densities of Divinycell H-grade foam are performed and the results Support this approach. Some preliminary results from two densities of Rollacell WF-grade are given as well. Static properties of foams scale with relative density and once this scaling can be obtained through various static tests and the same scaling appears to be valid for both crack propagation rates and fatigue properties of foams. The implication of this is that once the fatigue behaviour of one relative density foam is established, one can predict the fatigue behaviour of all other relative density foams within the same class of materials.

  • 34.
    Zenkert, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Shipsha, Andrey
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Burman, Magnus
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Fatigue of closed cell foams2006In: Journal of Sandwich Structures and Materials, ISSN 1099-6362, E-ISSN 1530-7972, Vol. 8, no 6, p. 517-538Article in journal (Refereed)
    Abstract [en]

    The static properties of foams scale with relative density and scaling can be obtained through various static tests. The same scaling appears to be valid for both crack propagation rates and fatigue properties of the foams. This implies that, once the fatigue behavior of one relative density foam is established, one can predict the fatigue behavior of all other density foams within the same class of materials. This study deals with fatigue of closed cell foams. The main idea is to use a few simple tests to predict tension-tension fatigue properties of foams. The required testing consists of crack propagation rate measurements and one tension-tension fatigue test performed at the yield stress of the foam. This data can then be combined to construct a synthetic S-N curve for the foam. Testing is performed on three densities of Divinycell H-grade and three densities of Rohacell WF-grade foam. A very simple fatigue model, based on an initial flaw approach, is used to link the crack propagation rate behavior of these foams with their unnotched fatigue life. This approach is backed up by the experimental results. The results obtained can be used to form some general conclusions about the fatigue of closed cell foams, at least of the types used herein.

  • 35. Zetterberg, T.
    et al.
    Astrom, B. T.
    Backlund, J.
    Burman, Magnus
    KTH, Superseded Departments, Aeronautical and Vehicle Engineering.
    On design of joints between composite profiles for bridge deck applications2001In: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 51, no 1, p. 83-91Article in journal (Refereed)
    Abstract [en]

    Techniques for joining of pultruded composite profiles for bridge-deck applications are designed and analyzed. It is shown that both adhesively bonded and bolted joints can be designed to fulfill stringent requirements, but it is clear that the former is the preferred alternative. The methodology used to analyze a large composite structure composed of modular construction elements and to determine the load transfer between composite profiles is described.

1 - 35 of 35
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