Long-term performance evaluation and prediction of composite materials and structures

目前，材料正在根据特定的产品需求进行设计，例如增加刚度，从而减轻重量，或提高耐腐蚀性和疲劳寿命。这种材料的例子是先进复合材料（ACM），其中基体（聚合物、铝/钛）由另一种更硬材料的纤维或颗粒增强。虽然通过引入第二相材料增强了某些机械性能（例如弹性模量、极限强度和耐腐蚀性或耐侵蚀性），但其他性能可能会受到不利影响（例如延展性、裂纹萌生、界面损伤、微塑性/蠕变、循环载荷下的粘结弱化和对温度/环境的耐受性）。因此，在评估这些先进工程材料的全部应用范围之前，需要对它们的长期行为进行彻底的调查。

At present materials are being engineered in response to specific product needs, e.g. increased stiffness which results in reduced weight, or improved corrosion resistance and fatigue lives. Examples of such materials are Advanced Composite Materials (ACM's) where the matrix (polymer, aluminum/titanium) is reinforced by fibres or particles of another stiffer material. While some of the mechanical properties are enhanced by the introduction of a second phase material (e.g. elastic modulus, ultimate strength, and corrosion or erosion resistance) other properties may be affected adversely (e.g. ductility, initiation of cracks, interfacial damage, micro-plasticity/creep, bond weakening under cyclic loading and resistance to temperature / environment). Thus a thorough investigation of the long-term behaviour of these advanced engineered materials is required before the full scope of their application can be assessed.