Abstract

The paper proposes a mechanical simulation model based on continuum damage mechanics and physical mesomechanics to describe the accumulation of dispersed damages in polycrystalline materials, considering that the main damaging factors are dispersed microcracks and internal stresses produced primarily by linear structural defects. From the proposed model follows a statistical limit state criterion consistent with failure conditions for brittle and ductile structural materials. The limit state criterion is applied to several typical cases of failure and elastic-to-elastoplastic strain transition in polycrystalline structural materials. Based on the model, an acoustic approach to damage assessments of structural materials is also proposed. With the approach, several acoustic effects are identified from the propagation of elastic pulses in a damaged material. Such effects can be useful for instrumental damage assessment of materials (specimens, structural elements) at any time of loading or operation. The acoustic approach can provide a basis for a method of measuring the damage parameters included in the model. The experimental data available to us suggest that the proposed approach to damage assessment is correct for structural materials and is promising for further experimental research to develop instrumental express methods of monitoring dispersed damages in metal structures exposed to thermomechanical loads.

中文翻译：

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多晶材料声学损伤监测的机械仿真模型

摘要

考虑到主要损伤因素是分散的微裂纹和主要由线性结构缺陷产生的内应力，提出了一种基于连续损伤力学和物理细观力学的力学模拟模型来描述多晶材料中分散损伤的累积。所提出的模型遵循与脆性和延性结构材料的失效条件一致的统计极限状态标准。极限状态准则适用于多晶结构材料中失效和弹塑性应变转变的几种典型情况。基于该模型，还提出了一种结构材料损伤评估的声学方法。通过这种方法，通过弹性脉冲在受损材料中的传播，可以识别出多种声学效应。这种效应可用于在加载或操作的任何时间对材料（样本、结构元件）进行仪器损伤评估。声学方法可以为测量模型中包含的损伤参数的方法提供基础。我们获得的实验数据表明，所提出的损伤评估方法对于结构材料是正确的，并且有望进行进一步的实验研究，以开发监测暴露于热机械载荷的金属结构中分散损伤的仪器表达方法。声学方法可以为测量模型中包含的损伤参数的方法提供基础。我们获得的实验数据表明，所提出的损伤评估方法对于结构材料是正确的，并且有望进行进一步的实验研究，以开发监测暴露于热机械载荷的金属结构中分散损伤的仪器表达方法。声学方法可以为测量模型中包含的损伤参数的方法提供基础。我们获得的实验数据表明，所提出的损伤评估方法对于结构材料是正确的，并且有望进行进一步的实验研究，以开发监测暴露于热机械载荷的金属结构中分散损伤的仪器表达方法。