轻质夹芯复合材料结构强度评估方法研究

由于具有高强度、高模量、重量轻、耐腐蚀的优良特点,复合材料在船舶上的应用逐渐成为研究热点.目前可查阅的关于船体复合材料结构强度校核的文献很罕见以及各种规范对船体复合材料结构强度校核尚未给出明确的说明.与各向同性材料的强度评估方法相比,复合材料强度评估有很大的不同.本文基于试验结果,分别采用壳单元、实体-壳单元和实体单元模型对复合材料结构进行数值分析,确定用于轻质夹芯复合材料结构强度评估的合理有限元模型.基于渐进损伤分析理论,采用Tsai-Wu失效准则和突降退化模型,对轻质夹芯复合材料的极限强度进行评估.结果表明:计及结果精确性与计算成本,可用壳单元模型分析复合材料结构的应力-应变分布;渐进损伤分析方法结合材料退化模型不仅有效地对复合材料结构的极限强度进行预测,同时还能判断材料的失效模式.

Investigation on Strength Assessment Methods for Lighten Sandwich Composite Structure

Composite materials has been used to application of marine engineering more widely due to its prominent characteristics such as high strength, high elasticity modulus, light weight and anti-corrosion.The literature on the strength of the hull composite structure is rare and the specifications of the hull composites have not yet given a clear explanation. There are many differences between composite materials and steel materials on strength assessment. In this paper we describe a strength assessment method of compositematerials. Based on the experimental results, the shell element model, solid element model and solid - shell element model were used to model the composite structure respectively for numerical simulation, which confirms a reasonable finite element modelfor strength assessment. Based on the progressive damage method,the Tsai-Wu failure criteria and dump degradation model were used to evaluate the ultimate strength of composite structures. The results show that taking into account the accuracy of the results and the calculation of the cost, the shell element model can be used to analyze the stress-strain distribution of the composite structure; The progressive damage analysis method combined with degradation model not only effectively predicts the ultimate strength of composite structures, but also judges the failure mode.