Development of experimental methods in the fields of non-linear fracture mechanics, investigating adhesive joints subjected to mixed-mode loading

粘合剂结合代表了这些天建立的连接技术。除了对刚度或阻尼性能的要求外，胶接接头在机械载荷作用下的断裂行为也是人们最感兴趣的。例如，接头失效的实际预测是汽车碰撞应用中最重要的标准之一。接头失效的实验表征在断裂力学测试中完成。所获得的结果被用来制定适当的模型，包括相应的参数，而特定的加载条件下所观察到的断裂行为有很大的影响。剥离和剪切载荷的组合称为混合模式载荷，线弹性断裂力学方法是实验表征的既定方法。这些方法不能不受限制地应用于粘合接头，其中包括显示非线性材料behavior.Within的框架内完成的研究项目，一种新的测试装置和两种新的评价方法已经开发出来，它不基于线弹性断裂力学的限制，因此可以应用于非线性接头行为。基本的新奇是一个可能的分离J积分到其贡献的单一断裂模式。另一个主要的新奇是测试控制的贡献或总J积分，它允许识别的牵引裂纹tip.The的主要目标是产生更深入的理解和进一步发展的建议的方法。这是通过对两种不同类型的粘合剂的实验和数值研究来实现的，以强调材料行为对测试结果的影响。此外，重点是扩展到一个新的测试设置，新的方法被应用。第二个测试设置生成关于另一种类型的混合模式加载的信息

Adhesive bonding represents an established joining technology these days. Beside requirements regarding stiffness or damping properties, the fracture behaviour of adhesive joint subjected to mechanical loading is of prime interest. As example, the realistic prediction of joint failure is one of the most important criteria in automotive crash applications.Experimental characterization of joint failure is done in fracture mechanical tests. The achieved results are used to formulate appropriate models including corresponding parameters, while the particular loading conditions have a huge influence on the observed fracture behaviour. Combined peel and shear loading is called mixed-mode loading, and methods of linear-elastic fracture mechanics are an established approach for experimental characterization. Those methods cannot be applied without limitations to adhesive joints, which consist of adhesives showing nonlinear material behaviour.Within the framework of a finished research project, a novel test setup and two novel evaluation methods have been developed, which do not underlie limitations of linear-elastic fracture mechanics and therefore can be applied to non-linear joint behaviour. The essential novelty is a possible separation of J-integral into its contributions to the single fracture modes. A further major novelty is test control on those contributions or on total J-integral, which allows identification of traction at the crack tip.The main goal is to generate deeper understanding and further development of the proposed methods. This is achieved by experimental and by numerical investigations on two different kinds of adhesives to emphasize the influence of material behaviour on test results. In addition, the focus is extended to a novel test setup, on which the novel methods are applied. The second test setup generates information on another type of mixed-mode loading