A perturbation technique is applied to construct the first-order perturbation model for the incremental indentation stiffness in normal frictionless indentation of an isotropic functionally graded medium (FGM) with a constant Poisson’s ratio and an in-depth variable elastic shear modulus. The FGM identification problem of determining the shear modulus function from the effective indentation shear modulus, which is measured as a result of indentation testing, is formulated and solved. It is shown that both the effective shear modulus and the relative adhesive (pull-off) force are sensitive to the type of material grading.

中文翻译：

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从压痕实验中恢复弹性 FGM 的深度相关剖面信息

应用微扰技术构建了具有恒定泊松比和深度可变弹性剪切模量的各向同性功能梯度介质（FGM）正常无摩擦压痕中增量压痕刚度的一阶微扰模型。制定并解决了由压痕试验所测得的有效压痕剪切模量确定剪切模量函数的FGM识别问题。结果表明，有效剪切模量和相对粘合（拉离）力都对材料分级的类型敏感。