Deformation tests and failure process analysis of an anchorage structure

In order to study the failure process of an anchorage structure and the evolution law of the body＇s defor- mation field, anchor push-out tests were carried out based on digital speckle correlation methods （DSCM）. The stress distribution of the anchorage interface was investigated using the particle flow numerical simulation method. The results indicate that there are three stages in the deformation and fail- ure process of an anchorage structure： elastic bonding stage, a de-bonding stage and a failure stage. The stress distribution in the interface controls the stability of the structure. In the elastic bonding stage, the shear stress peak point of the interface is close to the loading end, and the displacement field gradually develops into a ＂V＂ shape, in the de-bonding stage, there is a shear stress plateau in the center of the anchorage section, and shear strain localization begins to form in the deformation field. In the failure stage, the bonding of the interface fails rapidly and the shear stress peak point moves to the anchorage free end. The anchorage structure moves integrally along the macro-cracl~ The de-bonding stage is a research focus in the deformation and failure process of an anchorage structure, and plays an important guiding role in roadway support design and prediction of the stability of the surrounding rock.

激光投影显示屏表面粗糙度的测量

显示屏是激光投影显示系统的一部分,其表面粗糙度直接影响着基于角度多样性的激光散斑抑制效果。在角度多样性散斑抑制原理的基础上,建立了被测显示屏表面粗糙度与散斑图样之间的相关性之间的联系。对显示屏表面粗糙度对照射角度和角度变化的敏感程度权衡,实验中将入射角和角度变化量分别固定在1°和0.0038°。为避免外界微扰和测试屏表面不平度对测试结果的影响,通过对被测显示屏5cm×5cm测试区域中选择9个子区域的测试结果进行平均,有效提高了测试精度。运用提出的方法确定4种材质显示屏的表面粗糙度分别为235.80,209.57,132.24和137.60μm,为设计有效降低激光散斑的投影显示屏提供了参考。