Formminneslegeringstråd-vävda energiabsorberande strukturer: Design, simulering och optimering

Shape memory alloy wire-woven structures are energy-absorbing structures capable of recovering their shape after undergoing large deformations. Traditional mechanical buffer structures have limited energy absorption capacity, while common energy-absorbing structures dissipate energy through plastic deformation but cannot be reused, each presenting its own limitations. In contrast, shape memory alloy wire-woven structures combine high energy absorption with reusability. This study employs a design approach integrated with finite element simulations and optimization to investigate the mechanical behavior and energy absorption characteristics of shape memory alloy wire-woven structures during loading and unloading under different configurations and parameters. The specific research objectives are as follows: (1) Propose an optimization design method for shape memory alloy wire-woven structures. The concepts of yarns, planes, and systems within wire-woven structures, defining various types of wire-woven wires and their relationships with planes and systems to provide a foundational basis for the design of wire-woven structures are established. Multiple performance evaluation criteria, such as loss factor, crushing force efficiency, and secant stiffness, to assess the performance of shape memory alloy wire-woven structures are introduced. Ls-Opt is utilized to construct a surrogate model and conduct optimization, employing the sequential response surface method to reduce the number of simulations. Through multiple iterative optimizations of the parameterized finite element model, an efficient optimization design for wire-woven structures is ultimately achieved. (2) Validate the finite element model in simulating shape memory alloy wire-woven structures with beam elements. In the finite element simulation of wire-woven structures, beam elements are used to discretize the shape memory alloy wires to simplify computation. First, the material model MAT30 in LS-DYNA is validated. Then, the beam element formulation is verified using experimental results of SUS304 stainless steel WBC structures. Additionally, the applicability of the beam element finite element model and the MAT30 material model to superelastic shape memory alloy wire-woven structures is validated through compression tests of NiTi 508 alloy springs and single-layer "Circular Spring Kagome" structures made of shape memory alloy. (3) Analyze the mechanical response of two wire-woven structures made of superelastic shape memory alloys. Finite element simulations are conducted for WBD and WBC structures, evaluating their performance using metrics such as the loss factor. The internal design parameters of the superior WBD structure are further optimized. Compared to the initial configuration, the optimized structure exhibits improvements in buffering and energy absorption performance. However, due to the structural form and inherent deformation modes, the improvement is limited. (4) Design and analysis of novel wire-woven structures using superelastic shape memory alloys. Based on the limitations of existing wire-woven structures, various new designs are proposed to enhance energy absorption and shape recovery capabilities. Finite element simulations and analyses are conducted to evaluate their performance. The mechanical behavior of these wire-woven structures is further examined under different loading conditions, with a focus on the effects of weaving density and other parameters. Among the new structures, the SWVW configuration demonstrates a stable deformation mode suitable for large compression deformations. As a result, SWVW is selected as the optimal structure for further optimization. The results indicate that, compared to the initial configuration, the optimized structure exhibits significant improvements in buffering and energy absorption performance, along with enhanced load-bearing capacity, providing a design approach to improve the damping characteristics of novel superelastic shape memory alloy wire-woven structures.