Structural Characteristics of Membranes & Shells and Applications to Non-Destructive Inspection using 3D Measurement and Holographic Interferometry

利用三维测量技术、全息干涉仪和电子散斑干涉仪（ESPI）研究了壳膜结构的结构特征及其在无损检测中的应用。所得结果可总结如下。(a)对玻璃钢复合材料层合板的振动特性进行了分析和实验研究。利用全息干涉仪获得了谐振振动模态。分析结果与实验结果吻合较好。玻璃钢缺陷板的无损检测是未来的主题。(b)在缺陷铝板的拉伸试验中，应用了ESPI。菌株的定位和发展已经能够可视化。未来的主题是利用有限元分析和断裂力学技术进行模拟。(c)应用ESPI观察了矩形拉伸膜结构在拉伸试验中的起皱产生过程。实验结果表明，起皱发生在载荷最小主应变的拐点处。此外，利用三维光学测量装置，对薄膜的褶皱进行了三维测量。未来的主题是开发高精度的测量设备，并通过理论分析进行仿真。(d)在使用暴露于丙酮蒸发的PMMA样品进行的双轴压缩试验中，宏观剪切断裂之前出现了一系列微小裂缝或裂纹。基于断裂力学的数值分析发现，即使在双轴压缩条件下，裂纹也存在一种特殊的排列方式，即构成裂纹阵列的每个裂纹都能打开，并表现出i型变形。(e)ESPI已用于观察混凝土硬化过程与钢筋混凝土梁弯曲和剪切开裂的产生和发展之间的收缩应变，并且可以可视化。未来的主题是通过FE、SPH和DEM Less等理论分析进行模拟

This study focused on structural characteristics of shell & membrane structures using three dimensional measurement, holographic interferometer and electronic speckle pattern interferometer(ESPI), and its applications to non-destructive inspection. The obtained results can be summarized as follows.(a)The vibration characteristics of FRP laminated composite plates have been analytically and experimentally investigated. The resonance vibration modes are obtained by using holographic interferometer. The vibration frequencies and modes between analytical and experimental results were good agreement. Non-destructive inspection of defective FRP plate is future theme.(b)In tensile test of defective aluminum plates, ESPI has been applied. Localization and development of strain have been able to visualize. The future theme is to simulate by FE analysis and fracture mechanics technique.(c)ESPI has been applied to observe a wrinkling generation process of tensile test of the rectangular tensioned … More membrane structures. It is found from the experimental results that wrinkling occurs at an inflection point of the load-minimum principal strain. Furthermore, using 3D-optic measuring device, the wrinkle of membrane has been measured three-dimensionally. The future theme is to develop high accuracy measurement equipment and to simulate by theoretical analysis.(d)In a biaxial compression test using PMMA samples exposed acetone evaporation, a macroscopic shear-faulting was preceded by an appearance of array of minute cracks or crazes. It was found from the fracture mechanics based numerical analysis that there exist a special arrangement in which each of crack constitutes the array can open exhibiting mode-I deformation even under biaxial compression.(e)ESPI has been applied to observe a shrinkage strain between concrete hardening process and the generation and development of bending and shearing cracking in RC beams, and it was possible to visualize. The future theme is to simulate by theoretical analysis such as FE,SPH,and DEM Less