湿热力载荷下复合材料层合板力学行为

MECHANICAL BEHAVIORS OF LAMINATED COMPOSITE PLATE SUBJECTED TO HYGRO-THERMO-MECHANICAL LOADING

复合材料层合结构在制造和使用过程中经常暴露在湿热环境中,复合材料湿热行为准确分析已是复合材料结构设计不可回避问题。然而,至今复合材料湿热分析理论模型仍存在如下问题:已有分析复合材料湿热问题理论模型多忽略层间应力连续条件,不能准确计算层间应力;近期复合材料湿热研究甚至假设湿热膨胀系数不随铺设角变化,此假设将产生误导。该文发展预先满足层间应力连续并考虑横法向应变的高阶整体-局部理论,构造三角形单元分析在湿热力载荷作用下复合材料力学行为,并研究湿热膨胀系数对湿热行为影响。

Laminated composite structures are usually exposed in hygrothermal environment as they are manufactured and applied in engineering practices. Thus, the hygrothermal behaviors of composites have to be considered in the design of composite structures. However, the following problems exist in theto-date theoretical models for hygrothermal analysis of laminated composites. Firstly, the continuity conditions of interlaminar stresses are usually neglected, as a result, it is difficult to obtain accurately the interlaminate stresses of laminated composites under hygrothermal environment. Moreover, in recent studies on hygrothermal problems, the thermal expansion coefficients are assumed to be independent of the angle of each layer, which may mislead the later researches. A higher-order global-local theory satisfying the continuity conditions of interlaminar stresses has been developed. Based on the proposed model, a triangular element is constructed to analyze the mechanical behaviors of laminated composites under hygro-thermo-mechanical loading. Moreover, effects of hygrothermal expansion coefficients on hygrothermal behaviors are also investigated.