Differential tomography of micromechanical evolution in elastic materials of unknown micro/macrostructure
Differential tomography of micromechanical evolution in elastic materials of unknown micro/macrostructure
复制标题
未知微观/宏观结构弹性材料中微机械演化的微分断层扫描
DOI：
10.1137/19m1305707
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
H. Haddar
中科院分区：
文献类型：
--
作者：
Fatemeh Pourahmadian;H. Haddar
引入差分演化指标用于复杂材料中微机械过程的 3D 时空成像，其中由于制造和/或老化而产生的渐进变化被容纳在先验未知或不确定结构的高度散射背景中。在这种情况下，建立了一个三层成像平台，其中：（1）域周期性地（或连续地）受到任意配置的照明和感测； (2) 通过精心构建的散射方程的非迭代解，部署连续的测量数据集，以提取域内部结构的分段散射特征； (3)然后使用所得的解序列来严格构造成像函数，该成像函数对于背景的未知静止分量（例如预先存在的间隙边界和气泡）具有适当的不变性。这就产生了差分指示器，专门恢复未知散射体网络内微机械演化的 3D 支持。直接散射问题在频域中表述，其中背景由随机分布的整体碎片组成。这些成分通过弹性和耗散未知的高度异质界面连接，这些界面受到时空演化的影响。内部边界的支撑被一组入射波依次照亮，从而在通用观察表面上捕获诱导的散射场。通过一组数值实验来说明所提出的成像指示器的性能，这些实验用于对具有随机分布的裂纹和气泡的渐进损伤区域进行时空重建。
Differential evolution indicators are introduced for 3D spatiotemporal imaging of micromechanical processes in complex materials where progressive variations due to manufacturing and/or aging are housed in a highly scattering background of a-priori unknown or uncertain structure. In this vein, a three-tier imaging platform is established where: (1) the domain is periodically (or continuously) subject to illumination and sensing in an arbitrary configuration; (2) sequential sets of measured data are deployed to distill segment-wise scattering signatures of the domain's internal structure through carefully constructed, non-iterative solutions to the scattering equation; and (3) the resulting solution sequence is then used to rigorously construct an imaging functional carrying appropriate invariance with respect to the unknown stationary components of the background e.g., pre-existing interstitial boundaries and bubbles. This gives birth to differential indicators that specifically recover the 3D support of micromechanical evolution within a network of unknown scatterers. The direct scattering problem is formulated in the frequency domain where the background is comprised of a random distribution of monolithic fragments. The constituents are connected via highly heterogeneous interfaces of unknown elasticity and dissipation which are subject to spatiotemporal evolution. The support of internal boundaries are sequentially illuminated by a set of incident waves and thus-induced scattered fields are captured over a generic observation surface. The performance of the proposed imaging indicator is illustrated through a set of numerical experiments for spatiotemporal reconstruction of progressive damage zones featuring randomly distributed cracks and bubbles.
影响因子：
2.1
作者：
M. Bonnet;F. Cakoni
通讯作者：
M. Bonnet;F. Cakoni