U.S.-Netherlands Cooperative Research: Evaluation of Mixed Mode Crack Propagation in Concrete Using Acoustic Emission

该奖项为迈阿密大学的Wimal Suaris教授在与荷兰代尔夫特理工大学土木工程学院Jan G.M.Van Mier教授的长期访问期间进行合作提供了部分支持。这些研究人员都对混凝土的混合型裂缝扩展感兴趣。他们将使用荷兰大学提供的双轴试验台，通过声发射监测对混凝土进行剪切断裂测试。这家荷兰集团提供世界级的实验室设施，使其处于实验性土木工程研究的前沿。他们开发了混合模式加载技术，这对拟议的研究至关重要。它的使用将与Suaris教授目前正在开发的一项新的声学监测技术相结合。他在无损检测技术方面有很强的分析背景和经验。这些互补的技能和他们在混凝土断裂方面的共同兴趣应该会导致非常富有成效的合作。混凝土结构的破坏涉及到大量的裂缝。使用断裂力学方法来表征混凝土的行为是很自然的。然而，今天人们普遍认为，经典断裂力学是为均匀的纯脆性材料发展的，不适用于混凝土。这是因为形成了一个相对较大的破裂过程区，经历了软化损伤。因此，在过去的十年里，人们对发展一种适用于混凝土的断裂力学进行了大量的研究。拟议的合作将有助于这一努力，并导致更好地了解混凝土在压力下的行为。

This award provides partial support for Professor Wimal Suaris of the University of Miami to collaborate during a long term visit with Professor Jan G. M. van Mier of the Faculty of Civil Engineering of Delft University of Technology, The Netherlands. These investigators share an interest in mixed- mode crack propagation of concrete. They will conduct shear fracture tests on concrete, with acoustic emission monitoring, using the biaxial test rig available at the Dutch University. The Dutch group offers world class laboratory facilities that place it at the forefront of experimental civil engineering research. They have developed the mixed-mode loading technique that is crucial for the proposed research. Its use will be combined with a novel acoustic monitoring technique currently being developed by Professor Suaris. He has a strong analytical background and experience in non-destructive testing technology. These complementary skills and their mutual interest in the fracture of concrete should result in a very fruitful collabo- ration. The failure of concrete structures involves a substantial amount of cracking. It is natural to use a fracture mechanics approach to characterize the behavior of concrete. However, it is generally accepted today that classical fracture mechanics, which was developed for homogeneous purely brittle materials, is inapplicable for concrete. This is because a relatively large fracture process zone develops which undergoes softening damage. Therefore, during the last decade, substantial research has been conducted on developing a form of fracture mechanics applicable for concrete. The proposed collaboration will contribute to that effort and lead to improved understanding of the behavior of concrete under stress.