Fracture modeling and experimental validation of Compacted Graphite Iron (CGI) specimens loaded under quasi-static conditions at room temperature are considered. Continuum damage mechanics coupled to plasticity is adopted to describe the evolution of damage. The damage production is based on a recently developed rate dependent damage evolution law, where the damage–plasticity coupling is modeled based on a damage driving energy that involves both stored energy and plasticity contributions. To describe ductile fracture accounting for stress triaxiality on the damage initiation, the inelastic contribution to the damage driving energy is controlled by the Johnson-Cook failure criterion. Three different damage models are defined based on elastic/inelastic damage driving energies. The damage models are validated against experiments on a set of notched specimens made of CGI with different notch geometries, where the global force-displacement curves and corresponding strain fields are obtained using digital image correlation technology. It is shown from the testing and the simulations that plastic strains generally need to be accounted for in order to properly describe the different failure processes of the CGI specimens. In addition, the ductile damage model is shown to more accurately predict the experimental force-displacement response as compared to the more simplistic stress drop, element deletion technique.

考虑了在准静态条件下于室温下加载的压实石墨铁（CGI）试样的断裂建模和实验验证。连续性损伤力学与可塑性相结合来描述损伤的演变。损害的产生是基于最近发展的与速率相关的损害演化定律，其中，损害与可塑性的耦合是基于损害驱动力建模的，该驱动力涉及存储的能量和可塑性的贡献。为了描述在破坏开始时考虑到应力三轴性的延性断裂，对破坏驱动能量的非弹性贡献由Johnson-Cook破坏准则控制。基于弹性/非弹性损伤驱动能量定义了三种不同的损伤模型。在一组由不同缺口几何形状的CGI制成的缺口试样上进行的实验验证了损伤模型，其中使用数字图像相关技术获得了整体力-位移曲线和相应的应变场。从测试和模拟中可以看出，通常需要考虑塑性应变，以正确描述CGI标本的不同破坏过程。此外，与更简单的应力降，元素删除技术相比，延性损伤模型显示出可以更准确地预测实验力-位移响应。从测试和模拟中可以看出，通常需要考虑塑性应变，以正确描述CGI标本的不同破坏过程。此外，与更简单的应力降，元素删除技术相比，延性损伤模型显示出可以更准确地预测实验力-位移响应。从测试和模拟中可以看出，通常需要考虑塑性应变，以正确描述CGI标本的不同破坏过程。此外，与更简单的应力降，元素删除技术相比，延性损伤模型显示出可以更准确地预测实验力-位移响应。