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一、引言断裂力学应用于金属、陶瓷、岩石乃至聚合物等材料已有若干年历史,并已取得了丰硕成果;在构件“缺陷”(裂缝)尺寸和外加应力之间找到了定量关系。如所周知:断裂力学溯源于A.A.Griffith脆裂断裂的学说,它使用匀质、弹性的玻璃做为研究对象;在这种情况裂隙一旦达到某一临界尺寸,立即自发地扩展下去,引发迅速,不稳定的裂缝传播迅速导致灾难性的致命后果。对于这种理想的脆性材料而言,不稳定裂缝的生长引发和断裂二者毋宁可做为同义语使用。在外观上这种裂缝的发展“势如破竹”,在过程中所释放的应变弹性能完全用于裂缝扩展所形成
I. INTRODUCTION Fracture mechanics has been used in metals, ceramics, rocks and even polymers for several years and has achieved fruitful results. A quantitative relationship has been found between the dimensions of components’ “defects” (cracks) and applied stresses. As is well known, fracture mechanics is traced back to the theory of AAGriffith brittle fracture. It uses homogeneous, elastic glass as the research object; in this case, once the fracture reaches a certain critical size, it will spontaneously expand and initiate rapid. The spread of unstable cracks quickly led to catastrophic and fatal consequences. For this ideal brittle material, both growth initiation and fracture of unstable fractures can be used synonymously. In the appearance, the development of this kind of crack is “like a broken bamboo.” The strained elastic energy released during the process is fully used for crack propagation.