Current antibody-based immunotherapy depends on tumor antigen shedding for proper T cell priming. Here we select a novel human CD40 agonistic drug candidate and generate a bispecific antibody, herein named BiA9*2_HF, that allows for rapid antibody-peptide conjugate formation. The format is designed to facilitate peptide antigen delivery to CD40 expressing cells combined with simultaneous CD40 agonistic activity. In vivo, the selected bispecific antibody BiA9*2_HF loaded with peptide cargos induces improved antigen-specific proliferation of CD8+ (10-15 fold) and CD4+ T cells (2-7 fold) over control in draining lymph nodes. In both virus-induced and neoantigen-based mouse tumor models, BiA9*2_HF demonstrates therapeutic efficacy and elevated safety profile, with complete tumor clearance, as well as measured abscopal impact on tumor growth. The BiA9*2_HF drug candidate can thus be utilized to tailor immunotherapeutics for cancer patients.

In this article, geometrical distortions of steel structures due to laser beam welding were analyzed. Two 700-mm-long U-beam structures were welded in overlap configurations: a double U-beam structure and a U-beam/flat structure. The structures were in different material combinations from mild steel to ultrahigh-strength steel welded with different process parameters. Different measures of distortions of the U-beam structures were evaluated after cooling. Significant factors of the welding process and the geometry of the structures were identified. Furthermore, welding distortions were modeled using two predictive finite element simulation models. The previously known shrinkage method and a newly developed time-efficient simulation method were evaluated. The new model describes the effects of expansion and shrinkage of the weld zone during welding and material plasticity at elevated temperatures. The new simulation method has reasonable computation times for industrial applications and improved agreement with experiments compared to the often used so-called shrinkage method.

Thin ultra-high strength steel shaped as 700 mm long U-beams have been laser welded in overlap configuration to study the influence of welding sequence on distortions. Three different welding directions, three different energy inputs as well as stitch welding have been evaluated, using resistance spot welding (RSW) as a reference. Transverse widening at the ends and narrowing at the centre of the beam were measured. A clear correlation was found between the weld metal volume and distortion. For continuous welds there was also a nearly linear relationship between the energy input and distortion. However, the amount of distortion was not affected by a change in welding direction. Stitching and RSW reduced distortion significantly compared to continuous laser welding.

The automotive industry is striving towards reduction of greenhouse gas emission by reducing product weight and improving fuel efficiency of their products. The introduction of lightweight materials have imposed greater pressure not only on the product development but also on manufacturing systems. One integral aspect of manufacturing systems, which is meeting these challenges is joining technology. In order to achieve successful joining of new automotive products, joining process planning must be equally successful.This research aims at improving process planning of joining by introducing digital tools into the process planning work method. The digital tools are designed to reduce lead times and increase accuracy of the process planning to realize more advanced, complex and environmentally friendly product solutions in the vehicles of the future.The research has two main focuses. Firstly, the joining process planning structure and organization have been analysed. The analysis has identified specific instances where digital tools can be introduced to improve the process planning and make it more efficient. Digital tools, such as numerical models for prediction and databases for re-use of knowledge, have been suggested for the process planning. An assessment of the impact of the introduction of these tools in an industrial test case has been performed to show the possible reduction in lead times.Secondly, geometrical distortions due to laser beam welding have been investigated, both by experimental trials and numerical modelling. The influences of design and process parameters on the distribution and magnitude of geometrical distortions have been established. Numerical models of different modelling detail and complexity have been developed and evaluated in order to find modelling approaches with reduced computation times aimed at industrial implementation. The predictive accuracy and computational efficiency of the numerical models have been assessed and evaluated with regard to industrial implementation.

Distortions of mild steel structures caused by laser welding were analyzed. One thousand-millimeter U-beam structures were welded as overlap joints with different process parameters and thickness configurations. Final vertical and transverse distortions after cooling were measured along the U-beam. Significant factors, which affect distortions, were identified. Heat input per unit length, weld length, and sheet thickness showed a significant effect on welding distortions. Furthermore, the welding distortions were modeled using FE simulations. A simplified and computationally efficient simulation method was used. It describes the effect of shrinkage of the weld zone during cooling. The simulations show reasonable computation times and good agreement with experiments.

Geometrical distortions occur while welding, but the understanding of how and why they occur and how to control them is limited. The relation between the weld width, weld metal volume, total energy input, width of hard zone and distortions when laser welding three different thin sheet steels with varying strength has therefore been studied. Weld metal volume and total energy input show a good correlation with distortion for one steel at a time. The best correlation with the when including all three steel grades was the width of the hard zone composed of weld metal and the martensitic area in the heat affected zone.

Process planning of spot welding for body-in-white automobile structures involves several experimental (physical) welding trials to set the process parameters. These experimental trials are crucial in ensuring the quality and efficiency of the process. However, due to the iterative nature of the work, running several experiments is costly and time consuming prolonging the overall development cost and time significantly. To minimize the cost and time, replacing the physical tests by digital (virtual) tests is an established approach although not often applied for spot welding. However, for a long chain of development process with several iterative loops, this is not a trivial task considering the availability of information and continuity of the work flow. This paper reports the work and results of an industrial case study conducted on spot welding of a body-in-white car pillar in a Swedish auto manufacturer. The aim of the study is to investigate and propose the necessary conditions required to replace a physical test by virtual tests in terms of validity and expedited execution of the process. Information sharing, knowledge reuse and streamlining the work flow have found to be critical condition for valid and rapid virtual tests.

Ultra high strength steels are frequently used within the automotive industry for several components. Welding of these components is traditionally done by resistance spot welding, but to get further productivity and increased strength, laser welding has been introduced in the past decades. Fusion welding is known to cause distortions due to built in stresses in the material. The distortions result in geometrical issues during assembly which become the origin of low joint quality due to gaps and misfits. U-beam structures of boron steel simulating B-pillars have been welded with laser along the flanges. Welding parameters and clamping have been varied to create different welding sequences and heat input generating a range of distortion levels. The distortions have been recorded dynamically with an optical measurement system during welding. In addition, final distortions have been measured by a digital Vernier caliper. The combined measurements give the possibility to evaluate development, occurrence, and magnitude of distortions with high accuracy. Furthermore, section cuts have been analyzed to assess joint geometry and metallurgy. The results show that final distortions appear in the range of 0–8 mm. Distortions occur mainly transversely and vertically along the profile. Variations in heat input show clear correlation with the magnitude of distortions and level of joint quality. A higher heat input in general generates a higher level of distortion with the same clamping conditions. Section cuts show that weld width and penetration are significantly affected by welding heat input. The present study identifies parameters which significantly influence the magnitude and distribution of distortions. Also, effective measures to minimize distortions and maintain or improve joint quality have been proposed. Finally, transient finite element (FE) simulations have been presented which show the behavior of the profiles during the welding and unclamping process.

Resistance spot welding (RSW) is the most common welding method in automotive engineering due to its low cost and high ability of automation. However, physical weldability testing is costly, time consuming and dependent of supplies of material and equipment. Finite Element (FE) simulations have been utilized to understand, verify and optimize manufacturing processes more efficiently. The present work aims to verify the capability of FE models for the RSW process by comparing simulation results to physical experiments for materials used in automotive production, with yield strengths from approximately 280 MPa to more than 1500 MPa. Previous research has mainly focused on lower strength materials. The physical weld results were assessed using destructive testing and an analysis of expulsion limits was also carried out. Extensive new determination of material data was carried out. The material data analysis was based on physical testing of material specimens, material simulation and comparison to data from literature. The study showed good agreement between simulations and physical testing. The mean absolute error of weld nugget size was 0.68 mm and the mean absolute error of expulsion limit was 1.10 kA.

Due to increased demands on reduced weight in automotive industries, the use of ultra high strength steels (UHSS) has increased. When laser welding UHSS ssheets, heating and cooling of the material will cause geometrical distortions and may cause low joint quality. 700 mm long U-beam structures of 1 mm thick boron steel simulating structural pillars in body-in-white constructions have been laser welded along the flanges with different welding speeds to investigate distortions and weld quality. The results show that final distortions appear in the range of 0-8 mm. FE simulation methods have also been presented which generally predict the distribution of welding distortions.