Thermomechanical interaction in the shear cutting affected zone

剪切切削是金属材料无屑分离的重要工艺。在质量评估方面，切削表面的形成是重要的。目前的许多研究涉及不同工艺参数对切削表面形成的影响，例如切削刃几何形状、切削速度和间隙。当达到剪切断裂极限时发生材料失效，这取决于变形和应力状态。因此，材料的应变率由应变、应变速率和温度决定。这些变量在切削过程中在剪切影响区相互作用。因此，本研究的范围是开发一种测量装置和评估方法，能够同步分析剪切带中的应变、应变速率和温度。通过测量切削间隙、切削刃几何形状和切削速度这三个工艺参数来评价材料行为。为此，建立了一种剪切切削工具，该工具允许在考虑冲压速度和冲压穿透的情况下，首次对切削影响区中的材料的局部应变、应变速率和温度进行原位高分辨率检测。测量数据的解释结合集成的切削力位移测量，使材料的行为在剪切切割过程中，直到裂纹萌生的扩展描述。在此基础上，推导出剪切有限元分析参数集的获取规范。测量设置和评估方法的开发和测试是重要的里程碑，也是开发用于预测切削表面形成的Meta模型的基础。

Shear cutting is an important process in chipless separation of metallic materials. In terms of quality assessment the formation of the cutting surface is important. Many present investigations deal with the influence of different process parameters, e.g. cutting edge geometry, cutting speed and clearance, on the formation of the cutting surface. Material failure occurs when the shear fracture limit is reached, which depends on the deformation and the stress state. Thereby, material behav-ior is decisively determined by strain, strain rate and temperature. This variables interact in the shear cutting affected zone during the cutting process. An overall analysis of this complex cause-effect relationships is not possible until now.Hence, the scope of this research is to develop a measurement setup and evaluation methodology enabling a synchronous analysis of strain, strain rate and temperature in the shear zone. The mate-rial behavior is evaluated by measuring the process variables having regard to the three process parameters cutting clearance, cutting edge geometries and cutting speed. For this a shear cutting tool is built up which allows an in-situ high resolution detection of local strains, strain rate and tem-perature of the material in the cutting affected zone for the first time having regard to the punch speed and the punch penetration. The interpretation of the measurement data in combination with an integrated cutting-force-displacement-measurement enables an extended description of the material behavior during shear cutting process until crack initiation. Based on that, specifications on how to acquire a parameter set for shear cutting finite element analysis are derived. The devel-opment and testing of the measurement setup and evaluation methodology is an important mile-stone and the basis for the development of a meta model for the prediction of cutting surface-formation.