The paper presents a methodology developed within the EURobust project (G1RD-CT-2002-00833 and IMS-Robust 97009, www.eurobust.net). Durability and robustness of components are combined effects of external loads, geometrical design, selected materials and manufacturing sequence. The influence of the manufacturing sequence has not yet been explored and implemented in the virtual product development process and this paper presents a new and unique method to help the engineer in invoking the effect of the manufacturing sequence on product properties. The methodology extracts and evaluates manufacturing parameters with a major influence on component durability. The method is a combination of engineering judgement, Variation Mode and Effect Analysis (VMEA), design of experiment plans for computer-based experiments, automatisation of Finite Element simulations and visualisation of results. The paper describes how to use the method when estimating the robustness of a forged steering knuckle where the deep rolling process was identified as the most important manufacturing process in the manufacturing sequence, using Failure Mode and Effect Analysis (FMEA). The impact on residual stresses, surface quality and deformation hardening from the deep rolling parameters such as tool diameter, hydrostatic pressure, circumferential spindle velocity, feed rate, etc was analysed using VMEA. A simulation model of the deep rolling process was developed and the variations of residual stresses as a function of the manufacturing parameters were simulated and analysed using graphical response surfaces. The method will help engineers to better control the design of components taking all aspects, including the manufacturing sequence, into consideration at the early design phase. The method will also increase the knowledge of how the manufacturing processes affect component durability. 

This paper describes the experiences gained when using numerical and empirical methods in order to predict the accumulated surface characteristics for a safety component after several forging steps, controlled cooling and blasting. The forging steps were simulated in a sequence using one Finite Element (FE) code. The output forging mesh was used as input to the cooling simulation but was too coarse in order to reflect surface characteristics. The decarburisation effect during cooling that may influence the surface characteristics was not included in the cooling model. An attempt to create a parametric model of the blasting machine with output residual stresses and hardness as a function of input residual stresses, hardness and process parameters indicated the need of further investigation concerning the physical phenomena during blasting in the machine. A new method was developed for analysing the influence of the blasted surface texture on the stress intensity. The measured residual stresses and hardness span caused by variations in the blasting process were successfully used together with the stress intensity factor as input to a fatigue strength analysis. In order to establish a seamless chain of models through the manufacturing sequence further development concerning cooling and blasting models is required.

Virtual methods for prediction of product properties induced by the manufacturing system may be a good support for product development and process optimisation. The shot peening process may increase component fatigue life by the introduction of compressive residual stresses and the goal of this literature survey was to investigate the industrial maturity of numerical models for shot peening simulation, developed in various R&D projects. The knowledge is based on the information in articles mainly presented at conferences arranged by the International Scientific Committee on Shot Peening. Some important aspects when virtually predicting residual stresses after shot peening are summarised. Several solutions were proposed with different geometric target conditions, material models and numbers of shots. A dynamic analysis with bilinear or multilinear hardening conditions where the target is a 3D block or cylinder of a small substrate below the surface may be a good approach. Also a pattern of several shots against the target should be considered. The state of the art concerning numerical models is still on a basic level and alternative methods, like parametric modelling, may therefore be a complement to numerical simulation. Here the user extracts polynomial relations between process parameters and residual stresses based on measurements.

The manufacturing of components requires several manufacturing process steps that are performed in a sequence, during which the raw material is progressively converted into finished parts. The aim with simulation of manufacturing sequences is to replicate the aggregate effects of the process steps on key features of the finished product and manufacturing features. With the support of a successful simulation methodology, it will thereby be possible for process planners to evaluate virtually and select process steps to be included in the manufacturing sequence and to optimize process parameters. The motivation to implement sequential simulation in industry is therefore strong and will reduce time and cost in process planning. The modelling and simulation of complete manufacturing sequences is, however, a challenge which may lead to unrealistic and time-consuming modelling efforts and extensive computational requirements. This is due to the often complex material transformations through several consecutive process steps. In order to adapt sequential simulation into an industrial environment, simplifications are therefore necessary. This paper proposes a method for simplified metamodelling of manufacturing sequences, using upstream selection of process steps and definition of interconnected models. The method is presented as an algorithm and will improve the efficiency in the modelling of manufacturing sequences. The usability of the algorithm is demonstrated with two industrial cases: a bevel gear pinion and a steering arm.

Machining of components may cause geometric distortions and thereby quality issues and increased costs. This paper presents an engineering approach of CAD/CAM based manufacturing simulation in order to be in control of geometric distortions after machining. The method utilises STEP AP209 for communication of CAD/CAM simulation data. The method improves the ability to optimise process parameters, geometry, and material, in order to fulfil the design requirements. The method supports concurrent design and process planning using 3D models in CAD/CAM and FEM.