Crack propagation processes in specially prepared concrete discs and rectangular specimens containing a single cylindrical hole or multiple holes of varying diameters have been studied both experimentally and numerica...Crack propagation processes in specially prepared concrete discs and rectangular specimens containing a single cylindrical hole or multiple holes of varying diameters have been studied both experimentally and numerically. In this research, the cracks coalescence paths in Brazilian disc and rectangular specimens made from rock-like material containing multi-holes are investigated. These concrete specimens are specially prepared from an appropriate mixture of Portland Pozzolana Cement （PPC）, fine sands, and water. The pre-holed Brazilian discs and rectangular specimens are experimentally tested under compression. The breakage load in the ring type disc specimens containing an axial hole with varying diameters is measured and the distribution of the induced lateral stress is obtained. The mechanism of cracks propagation in the wall of the ring type specimens is also stud- ied. In the case of multi-hole Brazilian disc and rectangular specimens, the cracks propagation and cracks coalescence are also investigated. These experiments are numerically modeled by a modified higher order displacement discontinuity method. It has been shown that the corresponding experimental and numerical results are in good agreement with each other. The results presented in this research vali date the accuracy and applicability of these crack analyses procedures.展开更多
伴随结构精细化、小型化的发展,薄板、薄壁管件等小尺寸构件得到应用,试样小型化对满足特殊取样要求和材料断裂韧度测试需求有重要工程意义,而基于非标小试样的材料断裂性能测试方法尚难满足需求。设计用于延性材料断裂韧度测试的C形环...伴随结构精细化、小型化的发展,薄板、薄壁管件等小尺寸构件得到应用,试样小型化对满足特殊取样要求和材料断裂韧度测试需求有重要工程意义,而基于非标小试样的材料断裂性能测试方法尚难满足需求。设计用于延性材料断裂韧度测试的C形环小试样,提出应用该类小尺寸试样获取材料延性断裂韧度的、基于量纲一载荷分离理论的规则化测试方法。分别采用C形环小试样和传统紧凑拉伸型(Compact tension,CT)大试样完成转子材料26Ni Cr Mo V11-5钢和压力容器材料A508-Ⅲ钢的J阻力曲线试验,讨论C形环小试样厚度、初始裂纹长度对试验结果的影响。结果表明,试样厚度和初始裂纹长度对C形环的J阻力曲线测试结果影响有限,但C形环试样裂尖具有更高的约束水平,由C形环试样得到的J阻力曲线明显低于CT试样的结果。展开更多
基金sponsored by Iran’s National Elites Foundation (INEF)
文摘Crack propagation processes in specially prepared concrete discs and rectangular specimens containing a single cylindrical hole or multiple holes of varying diameters have been studied both experimentally and numerically. In this research, the cracks coalescence paths in Brazilian disc and rectangular specimens made from rock-like material containing multi-holes are investigated. These concrete specimens are specially prepared from an appropriate mixture of Portland Pozzolana Cement （PPC）, fine sands, and water. The pre-holed Brazilian discs and rectangular specimens are experimentally tested under compression. The breakage load in the ring type disc specimens containing an axial hole with varying diameters is measured and the distribution of the induced lateral stress is obtained. The mechanism of cracks propagation in the wall of the ring type specimens is also stud- ied. In the case of multi-hole Brazilian disc and rectangular specimens, the cracks propagation and cracks coalescence are also investigated. These experiments are numerically modeled by a modified higher order displacement discontinuity method. It has been shown that the corresponding experimental and numerical results are in good agreement with each other. The results presented in this research vali date the accuracy and applicability of these crack analyses procedures.
文摘伴随结构精细化、小型化的发展,薄板、薄壁管件等小尺寸构件得到应用,试样小型化对满足特殊取样要求和材料断裂韧度测试需求有重要工程意义,而基于非标小试样的材料断裂性能测试方法尚难满足需求。设计用于延性材料断裂韧度测试的C形环小试样,提出应用该类小尺寸试样获取材料延性断裂韧度的、基于量纲一载荷分离理论的规则化测试方法。分别采用C形环小试样和传统紧凑拉伸型(Compact tension,CT)大试样完成转子材料26Ni Cr Mo V11-5钢和压力容器材料A508-Ⅲ钢的J阻力曲线试验,讨论C形环小试样厚度、初始裂纹长度对试验结果的影响。结果表明,试样厚度和初始裂纹长度对C形环的J阻力曲线测试结果影响有限,但C形环试样裂尖具有更高的约束水平,由C形环试样得到的J阻力曲线明显低于CT试样的结果。
