Calculation of 3D internal displacement fields from 3D X-ray computer tomographic images
Calculation of 3D internal displacement fields from 3D X-ray computer tomographic images
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根据 3D X 射线计算机断层扫描图像计算 3D 内部位移场
DOI：
10.1098/rspa.1995.0057
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
S. M. Song
中科院分区：
文献类型：
--
作者：
Zhenyu Zhou;C. Synolakis;R. Leahy;S. M. Song
对于满足连续介质力学小位移梯度近似的场，提出了一种计算具有复杂内部结构的三维复合物体与永久变形相关的内位移场的新方法。我们从一系列3D X射线计算机断层扫描(CT)图像中计算位移场。通过假设层析图像的强度代表一种不可压缩的守恒性，我们建立了一个用于估计位移场的约束非线性回归模型。然后使用逐次线性逼近，并使用变分求解每个线性辅助问题。我们用有限组的线性方程组，用有限差分方法逼近得到的欧拉-拉格朗日方程。我们在多分辨框架下使用共轭梯度算法来求解这些方程。我们用平面剪切流的合成图像对我们的方法进行了验证。最后，确定了加载到永久变形状态的圆柱形沥青/集料芯体内部的三维位移场。
We present a new method for computing the internal displacement fields associated with permanent deformations of 3D composite objects with complex internal structure for fields satisfying the small displacement gradient approximation of continuum mechanics. We compute the displacement fields from a sequence of 3D X-ray computed tomography (CT) images. By assuming that the intensity of the tomographic images represents a conserved property which is incompressible, we develop a constrained nonlinear regression model for estimation of the displacement field. Successive linear approximation is then employed and each linear subsidiary problem is solved using variational calculus. We approximate the resulting Euler-Lagrange equations using a finite set of linear equations using finite differencing methods. We solve these equations using a conjugate gradient algorithm in a multiresolution framework. We validate our method using pairs of synthetic images of plane shear flow. Finally, we determine the 3D displacement field in the interior of a cylindrical asphalt/aggregate core loaded to a state of permanent deformation.