对扭力测试的需求
许多产品和组件在其正常使用过程中会承受扭转力。 With torsion testing, designers are able to understand real-life service conditions, improve product quality, validate design, and also verify actual production process. Products such as biomedical stents, implantable orthopedic devices, fasteners, and automotive steering/suspension components are examples of products that are subjected to torsional stresses in their typical service environment.
The types of torsion testing utilized vary depending on the information desired from the material or component. Examples include biomedical type torsional testing for bone, bone screws and plate assemblies. Whether it is for characterizing a torsion insertion test for bone screws, or performing basic failure tests, proof tests, or manufacturing process validation, some type of torsional testing method can be designed and performed to meet the needs of each application.
类比拉伸/压缩测试
Torsion tests are typically performed to determine the torsional properties of a material or component. Analogous to the properties determined during a tensile/compression test, the “torque versus angle” diagram, for example, is similar to a “stress versus strain” curve.确定的特性包括：
- 剪切弹性模量
- 剪切屈服强度（扭转弹性极限）
- 剪切极限强度
- 剪切断裂模量
- 延展性（沿删除/广泛剪切面）
- 脆性断裂（垂直于删除/广泛拉伸应力，45 度）
扭力测试类型
扭力测试适用于仅进行旋转运动的应用或是兼具轴向力（拉伸或压缩）和扭转力（力矩）的应用。测试类型如下：
仅扭力：仅向样本/装置施加扭转负载（转矩或力矩）。
轴向 – 扭力：同时施加轴向（拉伸或压缩）负载和转矩。
断裂测试：扭转产品、组件或样本直至断裂。
