航空热塑性复合材料非联合塑性流动法则改进与参数辨识OA
An Improved Non-Associative Plastic Flow Rule and Parameter Identification for Aerospace Thermoplastic Composites
发展成熟的塑性流动法则对于促进航空热塑性复合材料层合板的抗冲击轻量化设计具有重要价值.热塑性复合材料复杂的塑性变形机制导致传统塑性流动法则难以准确描述其力学行为.针对上述问题,本文基于单一参数塑性流动法则,进一步考虑非联合塑性、拉压不对称效应及横向塑性泊松比等因素,提出改进的塑性流动法则,推导了拉伸、压缩和剪切载荷作用下屈服函数中静水压力系数的约束条件,建立了强化应力、等效塑性应变与单轴应力、应变之间的函数关系.通过开展碳纤维增强聚醚醚酮基复合材料(CF/PEEK)平面偏轴拉伸试验,提出了平面内剪切应力系数与屈服函数中静水压力系数的辨识方法,并进一步给出了平面外剪切应力系数的辨识方案.研究结果表明,改进后的流动法则为一参数法则的扩展形式,其受偏轴角度、平面内剪切应力系数及静水压力系数影响,弥补了传统模型中未考虑静水压力效应的缺陷.通过结合无导数法和梯度下降法,可以实现平面内剪切应力参数及静水压力系数的准确辨识,参数辨识误差在5％以内.基于修正的航空热塑性复合材料塑性流动模型,可以提升多轴载荷下材料行为的预测能力,为航空航天领域的复合材料结构设计与安全性评估提供理论依据.
The development of the plastic flow has significant value for promoting the lightweight and impact-resistant design of aerospace thermoplastic composite laminates.The complex plastic deformation mechanisms of thermoplastic composites make it difficult for traditional plastic flow laws to accurately describe their mechanical behavior.To address these issues,this paper builds upon the one-parameter plastic flow law proposed,further incorporating factors such as non-associated plasticity,tension-compression asymmetry effects,and transverse plastic Poisson's ratio to propose an improved plastic flow law.In this paper,the constraint conditions for the hydrostatic pressure coefficient in the yield function under tensile,compressive,and shear loading were derived,and the functional relationships between the hardening stress,equivalent plastic strain,and uniaxial stress and strain were established.By conducting off-axis tensile tests on carbon fiber-reinforced polyether ether ketone(CF/PEEK)composites,an identification method for the in-plane shear stress coefficient and the hydrostatic pressure coefficient in the yield function was proposed,along with a further scheme for identifying the out-of-plane shear stress coefficient.The results show that the improved flow law is an extended form of the one-parameter law,influenced by the off-axis angle,in-plane shear stress coefficient,and hydrostatic pressure coefficient,thereby addressing the deficiency of traditional models that neglect the hydrostatic pressure effect.By combining derivative-free methods and gradient descent methods,accurate identification of the in-plane shear stress parameter and hydrostatic pressure coefficient can be achieved,with parameter identification errors within 5％.Based on the corrected aerospace thermoplastic composites plasticity flow model,the prediction capability for material behavior can be improved under multi-axis load,thus providing therictical basis for composite structure design and safety evalution in aerospace.
刘鹏飞;郭芝彪
浙江大学,浙江舟山 316021浙江大学,浙江舟山 316021
航空航天
航空热塑性复合材料抗冲击性能非联合塑性拉压不对称横向塑性泊松比参数辨识
aerospace thermoplastic compositesimpact resistancenon-associative plasticitytension and compression asymmetrytransverse plastic Poisson's ratioparameter identification
《航空科学技术》 2026 (5)
15-22,8
国家自然科学基金(52475171)航空科学基金(2023M057076001) National Natural Science Foundation of China(52475171)Aeronautical Science Foundation of China(2023M057076001)
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