轻质金属薄壁梁大变形弯曲力学行为与设计优化研究

轻质多胞薄壁梁和薄壁拱梁具有良好的能量吸收和耐撞性能，在航空航天、汽车等运载工程的安全防护领域具有广泛的应用前景。本项目针对三点弯曲条件下，金属薄壁直梁和拱梁的大变形弯曲力学行为进行研究，采用实验研究、数值模拟、理论分析及优化设计相结合的研究方法，明确薄壁梁在三点弯曲条件下的变形模式和吸能特性，分析主要结构参数和加载条件对弯曲力学响应的影响，建立与变形模式相对应的能量耗散理论分析模型，获得弯曲力学响应的理论预测方法，探寻提高薄壁梁弯曲吸能效率的有效途径，并采用结构优化设计方法进一步提升结构的耐撞性能。项目预期将揭示横向弯曲条件下金属薄壁梁的变形和能量耗散机理，建立其弯曲力学响应的理论预测方法，掌握进一步提升其性能的有效手段及相关结构的最优化设计规律。项目的研究成果将为金属薄壁梁的耐撞性设计提供理论依据，并为进一步提高其吸能效率提供新的方法和思路，促进我国安全防护技术及相关学科的应用和发展。

Lightweight multi-cell thin-walled beams and arched thin-walled beams possess excellent energy absorption and crashworthiness performances and have extensive application prospects in the field of structural safety and protection for vehicle engineering including aerospace, automobile and etc. This project aims to investigate the large deformation mechanical behaviors of thin-walled straight and arched metal beams under three-point bending. Experimental study, numerical simulation, theoretical analysis and structural optimization will be employed jointly in this research. The deformation modes and energy absorption characteristics of the thin-walled beams under three-point bending will be investigated. The effects of major structural parameters and loading conditions on the bending responses will be analyzed. Theoretical models corresponding to the deformation modes will be established and analytical solutions on the bending responses of the beams will be derived. Effective approaches to improve the energy absorption efficiency of the thin-walled beams will be explored and structural optimization method will be employed to further improve the structural crashworthiness. The project is expected to reveal the deformation and energy dissipation mechanisms of thin-walled metal beams under transverse bending, to establish theoretical methods to predict their bending responses, to master effective methods to further improve their performances, and to obtain the principles of optimal designs of the related structures. The research results of the project will sever as a theoretical basis for the crashworthiness design of thin-walled metal beams, provide novel approaches and ideas to further improve the energy absorption efficiency of the structures, and promote the applications and development of safety protection techniques and related subjects in China.