由于中子具有较高的穿透能力, 利用中子衍射容易获得块状试样内部特定位置的三维点阵面间距, 从而实现应变/应力分布的较准确评价。首先介绍了各种应力测试技术的研究现状以及角度分散法中子衍射应力测试技术的基本原理; 然后结合冲压成型试样的强度评价、复层钢板拉伸变形后的残余应变评价以及负荷条件下钢筋混凝土中钢筋的应力分布等中子衍射典型试验研究, 说明角度分散法中子衍射应力测试技术在国外已广泛应用于工程结构件与材料内部应力的定量研究; 最后展望了角度分散法中子衍射应力测试技术在国内的研究前景。

Because of the high penetrability of neutron beam in general metallic materials, neutron diffraction may easily acquire the three-dimensional information of polycrystalline diffraction from a well-defined gauge volume in any internal position of a structural material specimen or a machine component and then precisely evaluate the strain/stress distribution. The essential theory of angle dispersive neutron diffraction stress measurement technique based on a nuclear reactor was introduced, followed with several typical research examples including the work hardening evaluation of a cold press formed automobile component, the residual stain evaluation of a multilayered steel plate after uniaxial tensile deformation and the stress distribution of steel bar in a steel bar enforced concrete structural component under loading, showing that the angle dispersive neutron diffraction technique has been widely applied to the quantitative evaluations on internal stresses of engineering components and advanced materials in the developed countries. The rapid development and broad application of this strain/stress measurement technique have been highly expected in china.