R Koloor S S, Karimzadeh A, Abdullah M R, Petrů M, Yidris N, Sapuan S M, Tamin M N
Department of Aerospace Engineering, Universiti Putra Malaysia, UPM Serdang 43400, Selangor Darul Ehsan, Malaysia.
Institute for Nanomaterials, Advanced Technologies and Innovation (CXI), Technical University of Liberec (TUL), Studentska 2, 461 17 Liberec, Czech Republic.
Polymers (Basel). 2021 Jan 22;13(3):344. doi: 10.3390/polym13030344.
The stiffness response or load-deformation/displacement behavior is the most important mechanical behavior that frequently being utilized for validation of the mathematical-physical models representing the mechanical behavior of solid objects in numerical method, compared to actual experimental data. This numerical study aims to investigate the linear-nonlinear stiffness behavior of carbon fiber-reinforced polymer (CFRP) composites at material and structural levels, and its dependency to the sets of individual/group elastic and damage model parameters. In this regard, a validated constitutive damage model, elastic-damage properties as reference data, and simulation process, that account for elastic, yielding, and damage evolution, are considered in the finite element model development process. The linear-nonlinear stiffness responses of four cases are examined, including a unidirectional CFRP composite laminate (material level) under tensile load, and also three multidirectional composite structures under flexural loads. The result indicated a direct dependency of the stiffness response at the material level to the elastic properties. However, the stiffness behavior of the composite structures depends both on the structural configuration, geometry, lay-ups as well as the mechanical properties of the CFRP composite. The value of maximum reaction force and displacement of the composite structures, as well as the nonlinear response of the structures are highly dependent not only to the mechanical properties, but also to the geometry and the configuration of the structures.
刚度响应或载荷-变形/位移行为是最重要的力学行为，与实际实验数据相比，在数值方法中它经常被用于验证表示固体对象力学行为的数学物理模型。本数值研究旨在研究碳纤维增强聚合物（CFRP）复合材料在材料和结构层面的线性-非线性刚度行为，以及其对单个/组弹性和损伤模型参数集的依赖性。在这方面，在有限元模型开发过程中考虑了一个经过验证的本构损伤模型、作为参考数据的弹性损伤特性以及考虑弹性、屈服和损伤演化的模拟过程。研究了四种情况的线性-非线性刚度响应，包括单向CFRP复合层压板（材料层面）在拉伸载荷下的情况，以及三种多向复合结构在弯曲载荷下的情况。结果表明，材料层面的刚度响应与弹性特性直接相关。然而，复合结构的刚度行为既取决于结构配置、几何形状、铺层，也取决于CFRP复合材料的力学性能。复合结构的最大反作用力和位移值，以及结构的非线性响应不仅高度依赖于力学性能，还依赖于结构的几何形状和配置。
