Multi-functional materials, such as fiber-reinforced composites, energy-absorbing materials, self-healing materials, 3D printing materials, hydrogel materials, etc., are widely utilized across various industries, including aerospace engineering, transportation, marine engineering, construction, sports facilities, and the medical industry, due to their programmable mechanical properties. These materials provide crucial structural support during routine service. However, apart from enduring quasi-static loading during application, multi-functional materials and structures may also encounter impact loading in diverse scenarios (e.g., bird impacts on aircraft, vehicle protection, physical protection, etc.). Therefore, it is of paramount importance and presents a considerable challenge to investigate mechanical properties such as strength, modulus, toughness, energy absorption capacity, failure mechanisms, etc., under different strain rates and loading conditions to ensure the safety and reliability of structures across various applications.

In this Methods Collection, our objective is to highlight a wide range of methods for investigating the mechanical properties of multi-functional materials and structures. This includes, but is not limited to, quasi-static loading, low-velocity impact, high-velocity impact, extreme environmental effects, theoretical modeling, finite element methods, molecular dynamic simulations, artificial intelligence, etc. Overall, this collection aims to provide innovative solutions for designing and manufacturing multi-functional materials.