Purpose: The properties of materials under impact load are introduced in terms of metal, nonmetallic materials and composite materials. And the application of impact load research in biological fields is also mentioned. The current hot research topics and achievements in this field are summarized. In addition, some problems in theoretical modeling and testing of the mechanical properties of materials are discussed.Design/methodology/approach: The situation of materials under impact load is of great significance to show the mechanical performance. The performance of various materials under impact load is different, and there are many research methods. It is affected by some kinds of factors, such as the temperature, the gap and the speed of load.Findings: The research on mechanical properties of materials under impact load has the characteristics as fellow. It is difficult to build the theoretical model, verify by experiment and analyze the data accumulation.Originality/value: This review provides a reference for further study of material properties.

Assembly sequence planning (ASP) plays a key role in the whole life circle of a product. ASP has a great impact on variation propagation, production quality and efficiency of the assembly process. This paper tries to provide the way to generate and optimise assembly sequence for compliant assemblies based on graph theory. Firstly, a liaison graph and adjacency matrix are used to describe the geometry of the compliant assemblies. Secondly, an assembly sequence is represented by a character string, whose length is the number of all parts. The conceptual tolerance analysis is used to evaluate feasible sequences. Finally, the hybrid particle swarm optimisation and genetic algorithm is presented to generate assembly sequences. The hybrid particle swarm optimisation and genetic algorithm is more effective than the particle swarm optimisation, the genetic algorithm, the matrix operation and the enumeration method for assembly sequence planning of compliant assemblies.

Auto-body compliant parts are easily deformed during clamping and welding, and fixture layout is very important to the final product quality. However, it is very difficult to design fixture layout because it needs to synchronously satisfy the requirements of assembly tolerance and gravity deformation, which are calculated by finite element analysis. This paper proposes a new method to optimise fixture scheme by a non-domination sorting social radiation algorithm (NSSRA). Firstly, unfeasible nodes are eliminated by four rules according to manufacturing experiences. Afterwards, a few groups are divided based on positions of all feasible nodes. N groups are optimised using NSSRA. Finally, the best fixture layout is generated by selecting the feasible points among the optimal groups in last step. A case study of inner hood is used to illustrate the proposed method, and the results suggest that NSSRA has better efficiency and higher accuracy than NSGA-II.