No abstract

The benefits of incorporating rubber interlayers in lightweight laminates, such as fiber‐metal laminates, in order to compensate for their usually undesirable dynamic behavior have been studied in previous works [1,2]. In such constrained‐layer damping laminates, the rubber layers undergo large deformations due to their comparably low stiffness. This motivates the consideration of large strain phenomena commonly found in rubbers even when global laminate deformations are small such as in linear dynamic analysis. This work specifically addresses the cyclic softening of filled rubbers commonly known as the Mullins effect. As this effect significantly influences the elastic properties of the material, a change in the dynamic behavior of the laminate is to be expected. A constitutive model based on the work of Dorfmann and Ogden [3] for the prediction of the cyclic softening as well as residual strains upon unloading is presented in this study. Special consideration is given to the implementation of the model for use in a commercial implicit finite element solver by building on the work of Connolly et al. [4]. The model is validated against experimental data and compared to a current state‐of‐the‐art model with regard to its predictive quality and computational efficiency. Furthermore, the experimental identification of material parameters for said model is addressed.

The integration of local metal structures into polymer components using Laser Powder Bed Fusion (PBF-LB/M) offers great potential regarding multifunctional lightweight structures. However, such process hybridization involves huge challenges. In order to reduce the temperature input into the less temperature-resistant materials, the use of lower laser powers in the interfacial region is essential. The resulting local sintering of the metal powder affects the thermal properties in the interfacial region, leading to a change in heat dissipation in the temperature-unstable material. A modeling approach oriented to selective laser sintering is presented for predicting the degree of sintering and associated thermal properties in the context of PBF-LB/M process simulation.

ÐA method to design a variable flux electric machine using no rare earth materials is proposed. Starting from a synchronous reluctance machine's rotor the electromagnetic and mechanical design goals are derived. To improve torque production radially magnetized low coercive field magnets are inserted in the rotor, allowing for a control of the rotor flux. The flux guidance is improved by removing the webs required for mechanical sturdiness, which is achieved instead by mold injecting fiber reinforced polymer into the flux barriers. On the basis of a large design of experiments and using Gaussian process regression models, the relation between the rotor design parameters and output torque as well as external fields in the magnets is investigated and an optimization is performed. The resulting machine design allows an operation with high torque without involuntary demagnetization. The potential of the polymer filled flux barriers is confirmed through structural mechanical analysis.Index TermsÐDesign of experiments, electric machines, finite element analysis, modeling, multi material design, optimization, reinforced polymers, rotor design, structural design This work was part of the research project ºReMosº (ºEffiziente Reluktanzmaschine fÈ ur effiziente MobilitÈ at ohne seltene Erdenº),financed through the Ministry of Science, Research, and Arts of the Federal State of Baden-WÈ urttemberg in the framework of ºInnovationscampus MobilitÈ at der Zukunftº.