ROTATING CRACK MODEL WITH TRANSITION TO SCALAR DAMAGE
ROTATING CRACK MODEL WITH TRANSITION TO SCALAR DAMAGE
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DOI：
10.1061/(asce)0733-9399(1998)124:3(277
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发表时间：
1998-03
期刊：
影响因子：
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通讯作者：
M. Jirásek;T. Zimmermann
中科院分区：
文献类型：
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作者：
M. Jirásek;T. Zimmermann
传统的涂抹裂缝模型的混凝土断裂是众所周知的，遭受应力锁定（这里的意思是虚假的应力转移广泛开放的裂缝），网格诱导的方向性偏差，并可能在加载过程的后期阶段的不稳定性。本文建议将标准旋转裂纹模型与标量损伤概念相结合来克服这些不足。该模型保留了旋转裂纹的各向异性特征，但不会在大开口裂纹间传递虚假应力。这是记录的例子，包括三点弯曲，楔劈，和四点剪切单边缺口试样。然后，该模型被扩展到一个非局部制剂，它不仅作为一个有效的本地化限制器，但也消除网格诱导的方向性偏差。由于旋转裂纹模型的负剪切刚度，向损伤的转变可以防止一种特殊类型的材料失稳。
Traditional smeared-crack models for concrete fracture are known to suffer by stress locking (meaning here spurious stress transfer across widely opening cracks), mesh-induced directional bias, and possible instability at late stages of the loading process. The present paper suggests to overcome these deficiencies by combining the standard rotating crack model with the scalar damage concept. The combined model keeps the anisotropic character of the rotating crack but it does not transfer spurious stresses across widely open cracks. This is documented by examples including the three-point bending, wedge splitting, and four-point shear single-edge-notched specimens. The model is then extended to a nonlocal formulation, which not only acts as an efficient localization limiter but also alleviates mesh-induced directional bias. Transition to damage can prevent a special type of material instability arising due to negative shear stiffness of the rotating crack model.