ALLCAL Earthquake Simulator
ALLCAL Earthquake Simulator
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ALLCAL 地震模拟器
DOI：
10.1785/0220120056
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发表时间：
2012
影响因子：
3.3
通讯作者：
S. Ward
中科院分区：
文献类型：
--
作者：
S. Ward
在这里，我将介绍ALLCAL，这是南加州地震中心(SCEC)的科学家正在开发的地震模拟器之一。本文集中在可能将ALLCAL与小组中的其他模拟器区分开来的方面(Tullis等人。，2012a)。因此，这里几乎没有具体的结果；然而，随附的一份概述文件(Tullis等人)。，2012b)汇编和比较ALLCAL和其他地震模拟器的输出。
任何地震模拟器的核心都是计算许多位错单元的应力和位移。ALLCAL在整个空间中使用三角形元素。接收器位置r处的应力t(R)和位移u(R)的静态值由(Hirth and Lothe，1982)！[GRAPHIC][1](1a)给出，其中！[GRAPHIC][2](1b)和！[GRAPHIC][3](2a)其中！[GRAPHIC][4](2b)
参照图1，方程式(1a)、(1b)和(2a)、(2b)中的变量向量和标量为！[图][5](3)
图1.
三角形位错的几何学。
符号μ和υ分别是刚性和泊松比，Δu=u+−u−是单元上位移的不连续性，u+是在选择！[GRAPHIC][6]的一侧测量的。在方程式Ω(2a)中，从r可以看出，元素所跨越的立体角度。当r穿过元素外部的面片平面时，Ω(R)为零。当r穿过元素内部面片的平面时，Ω(R)具有±2π不连续性。Ω(R)给出了公式1(2a)在元素上的位移跳跃！[图形][7]。跳跃Δu既可以具有法线分量，也可以具有切线分量。立体角度从！[GRAPHIC][8](4)其中！[GRAPHIC][9]找到
Ω(R)的符号被认为与分子的符号相同。请不要将方程式(4)中的向量R1和R3与标量…混淆
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Here I introduce ALLCAL, one of the earthquake simulators being developed by scientists of the Southern California Earthquake Center (SCEC). This article focuses on aspects that may differentiate ALLCAL from other simulators in the group (Tullis et al. , 2012a). Accordingly, few specific results are included here; however, an accompanying overview paper (Tullis et al. , 2012b) assembles and compares outputs from ALLCAL and other earthquake simulators.
The heart of any earthquake simulator is the calculation of stresses and displacements from many dislocation elements. ALLCAL uses triangular elements in a whole space. Static values of stresses t ( r ) and displacements u ( r ) at receiver position r are given by (Hirth and Lothe, 1982) ![Graphic][1] (1a)where ![Graphic][2] (1b)and ![Graphic][3] (2a)where ![Graphic][4] (2b)
Referencing Figure 1, variable vector and scalar quantities in equations (1a), (1b) and (2a), (2b) are ![Graphic][5] (3)
Figure 1.
Geometry of a triangular dislocation.
The symbols μ and υ are rigidity and Poisson’s ratio, respectively, and Δ u = u +− u − is the discontinuity of displacement across the element, with u + measured on the side where ![Graphic][6] is chosen. Ω( r ) in equation (2a) is the solid angle spanned by the element as seen from r . Ω( r ) goes through zero when r passes through the plane of the patch outside of the element. Ω( r ) has a±2 π discontinuity when r passes through the plane of the patch inside of the element. Ω( r ) gives equation (2a) a displacement jump of ![Graphic][7] across the element. The jump Δ u can have both normal and tangential components. The solid angle is found from ![Graphic][8] (4)where ![Graphic][9]
The sign of Ω( r ) is taken to be the same as that of the numerator. Please do not confuse vectors R 1 and R 3 in equation (4) with scalars …
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