To designing various types of components that work in operation under the simultaneous effect of normal stresses, σ, and shear stresses, τ, is important to determine and know the behavior of materials under fatigue compound stress states. A device constructed to introduce into a specimen a state composed of normal and shear stresses is presented herein. The device is intended for performance under fatigue tests under combined tensile and torsional loading and can be mounted on a monoaxial fatigue machine. Variation of the combinations of normal and shear stresses is given by the possibility to change the cams to different inclination angles. We present a method of calculating the normal and shear stresses based on the parameters provided by a universal testing machine. Fatigue data for 6061 aluminum alloy are presented for several combinations of tensile and torsional loading. The fatigue limits, σ₀–τ₀, obtained by biaxial testing of the cylindrical specimens, were used to construct the σ–τ diagram. The calculation relations resulting from the use of the device for normal and shear stresses are deduced and presented. The calibration of the device is presented by means of a sample on which two electrotensometric transducers are mounted. The main feature of the device is its simplicity, based on the original idea of using a rigid cam that forces the central shaft to transform a translational movement received from the testing machine into rotational and translational movements using the inclined channel in the cam.

设计在正常应力σ和剪切应力τ同时作用下工作的各种类型的部件，对于确定和了解材料在疲劳复合应力状态下的行为非常重要。本文提出了一种构造成将由法向应力和剪切应力组成的状态引入样品的装置。该设备旨在在承受拉伸和扭转载荷的疲劳测试下发挥性能，并且可以安装在单轴疲劳机上。通过将凸轮更改为不同的倾斜角度，可以得出法向应力和剪切应力组合的变化。我们提出了一种基于万能试验机提供的参数计算法向应力和剪应力的方法。给出了6061铝合金在拉伸和扭转载荷的几种组合下的疲劳数据。疲劳极限，σ通过对圆柱试样进行双轴测试获得的₀ –τ ₀被用于构建σ–τ图。推导并提出了由于使用该装置的法向应力和剪切应力而产生的计算关系。该设备的校准通过一个样品进行，该样品上安装了两个电张力传感器。该设备的主要特征是其简单性，其基于使用刚性凸轮的最初想法，该刚性凸轮迫使中心轴使用凸轮中的倾斜通道将从测试机接收到的平移运动转换为旋转和平移运动。