【摘要】 针对唐山等大地震前出现的“形变空区”现象,依据实验和理论对应变空区进行了探讨. 实验过程中采用焦散线法、实时全息干涉计量方法(激光)图像摄影记录,同时进行微破裂(声发射)记录.依据固体损伤理论,结合微破裂定位对应变空区进行研究,得出两点结论:①应变空区在线弹性情况下出现是一种必然现象,且应变空区的位置相对稳定,与裂纹端部的应力集中相对应;②应变空区内几乎不发生微破裂.微破裂总是从高应力区产生,且几乎就发生在应力集中区与应变空区相联的条带内,最终表现为微破裂(声发射)的带状或成丛分布.主破裂总是从应变核(焦散阴影区)开始,然后向应变空区急剧发展,形成主大破裂,最终导致试样崩溃.更多还原

【Abstract】 Based on the phenomena, which the deformation gap was observed before the Tangshan Great Earthquake, this paper discusses the strain gap on test and theory. The (strain) patterns were recorded photographically by real-time holographic interferometry and shadow optical method of caustics, as soon as the loading process had been started. In the meantime, the AE (acoustic emission) signals were recorded by a microcrack information storage-analysis system. According to damage theory and location of microfracture, we have studied the stain gap and gained: ①it is necessary that strain gap appears under the condition of linear elasticity theory, and its situation is relatively stable, corresponding to stress concentration. ②Microfractures, which appear initially at area of high stress, occur rarely at the strain gap, and their locations are finally in the zone between the stress concentration area and the strain gap, which indicate the clusters or groups. However, the major macro fracture (final rupture) started from the shadow areas, and then grew quickly towards the strain gaps, which resulted in failure of sample.更多还原