1·The axes of principal stress rotated before earthquake.
震前主应力轴的旋转。
2·There are some differences of principal stress between secondary tectonic areas.
不同构造区主应力方向存在一定的差异。
3·The principal stress traces represent the directions of principal stresses inside an object.
主应力迹线是代表主应力方向的曲线簇。
4·The beginning of crack is vertical along the orientation of maximum horizontal principal stress.
初裂缝是沿着最大水平主应力方向的垂直缝。
5·The maximUm difference of failure strength among various principal stress direction is up to 30%.
不同主应力方向的破坏强度最大差别可达30%。
6·Integrating the minimum principal stress principle, the re-fracturing crack azimuth is determined.
再结合最小主应力原理，确定重复压裂裂缝方位。
7·At the beginning of loading, the major principal stress centralize in a triangle area under the lap.
刚开始加载时，最大应力集中在搭接面以下的一个三角形区域内。
8·In the article, a simple method is discussed to confirm the principal stress direction un-den the plane stress condition.
文章给出了一种判断平面应力状态主应力方向的简便方法。
9·The direction of the major principal stress in a region remains the same from tens of meters to 4000 meters below surface.
一个地区的主压应力方向在地下几十米至4000米大体是一致的。
10·The measured maximum horizontal principal stress orientation in North China by different methods were compared in this paper.
本文分析、比较了由不同方法测得的华北地区最大水平主应力方向。