基于边界位移的复合材料力学参数无损反演方法

Nondestructive identification of the mechanical properties of layered structures based on surface displacements

非均质材料参数识别在工程学、医学以及生物力学等众多领域具有重要意义。目前求解材料参数识别这类反问题主要采用优化方法,通常需要已知结构的全场位移信息,使含有位移的目标函数最小化,从而获得材料参数分布。然而在实际工程中,结构内部的位移较难测量且测量精度低。因此,本文拟提出一类仅利用边界位移就能进行非均质材料参数分布反演的方法。与一般基于全场位移的反演算法相比,基于边界位移场的反演算法,可在全场位移较难测得时,仍能较好地重建非均质材料的力学参数。本文拟利用该方法对复合材料层合板模型进行材料参数反演,验证本文方法的可行性,并分析不同组数测量边界位移场对反演结果的影响。本文提出的基于边界的非均质材料反演方法对结构的损伤识别和无损检测具有重要意义。

Identification of heterogeneous material property distributions is of great significance in various engineering fields.In general,the optimization-based inverse methods are used to solve the inverse identification problems,which requires knowledge of the full field displacement throughout the domain of interest.However,it is highly difficult to measure the displacements in the interior part of the structure with high accuracy.Therefore,we propose a novel approach which is capable of characterizing the heterogeneous mechanical property distribution of layered structures merely by using the surface displacement datasets.Compared with the reconstructed results by the full-field displacement measurement,the proposed inverse algorithm based on surface displacements can still reconstruct the heterogeneous mechanical parameters of composite structures with decent accuracy.We have also performed a number of the numerical experiments on laminated structures and successfully show the proof of the concept of the proposed method.The inverse method based on the surface deformation might have great potential for structural damage identification and nondestructive testing.