受力零件或构件在形状尺寸突然改变处出现应变显著增大的现象。应变集中处就是应力集中处。某横截面上的局部最大应变与该截面名义应变之比，称为应变集中系数。名义应变由名义应力和材料的应力应变关系算得。当应力和应变都在弹性范围内时，应变集中系数与应力集中系数是相等的。在弹性范围内，用弹性理论或光弹性方法确定的应力集中系数，称为弹性应力集中系数，或称理论应力集中系数用K表示。
获得了应变集中系数和弹塑性边界区随载荷变化的规律；
The variation of the strain concentration factors and the yield boundaries with loading levels were determined.
本文提出了双频自动网格法，在应变集中区域增加节点。
This paper presents a double frequency automated grid method, which applies more nodes in the stress concentration field.
试验结果还说明复合材料边缘有提高应变集中系数的效应。
The experimental result also shows that composite edge has the effect of increasing strain concentration factor.
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