## 1 Introduction  
In recent years, scroll compressors have been widely used in the automobile industry. They are operated under axial and radial loading conditions [1]. The rotation of the scroll leads to pressure and temperature changes. Thus, reliability is an important issue for the scroll. [PERSON] [2] attempted to simulate the pressure using ANSYS software. This research studied thermal stress during operation. Furthermore, [PERSON] [3] examined fatigue simulation via nCode DesignLife. [PERSON] used Dang Van analysis to assume the pressure during the operation. The dynamic model was studied by [PERSON] et al. [4]. He defined the scroll compressor's dynamic motion using dynamic characteristics such as pressure distribution, tangential force, and axial force. Furthermore, the accelerated condition was studied by [PERSON] [5]. This study carried out research about wear under the accelerated condition. By using temperature as a parameter, we can define the crack initiation condition more thoroughly. Various types of gas force in scroll compressors were considered by [PERSON] et al. [6]. By calculating the axial and radical force of gas during cycle, they ran the ANSYS program to calculate the deformation of the scroll. [PERSON] [7] studied rotation speed. In [PERSON]'s study, the structure received axial, tangential and friction forces. For various RPM, they calculated force, which is sometimes more serious for the structure than pressure. After these processes, they predicted fatigue life with the stress-lifecurve of the material. To reduce the contact force, [PERSON] [8] applied diamond-like carbon (DLC) film to the compressor. By reducing friction force, resistance can be reinforced. The commonality of the studies [2; 3; 4; 5; 6; 7] is that they only calculated regular operation, and did not consider the scroll compressor itself. However, during the operation, the scroll compressor came under an unexpected loading condition, specifically, contact with the counterpart, i.e., the fixed scroll. Although previous research mentioned that the scroll compressor easily succumbs to failure during the operation, there is only a small amount of research which concentrates on the scroll compressor itself. Even though they ran the finite element method (FEM) for the scroll compressor, the validation of the structure was operated under the operating condition, which was dominated by pressure and thermal conditions in those references. Thus, the design of more conservative experiments is needed, which was not studied in previous research. To achieve this requirement, the study modified the scroll compressor to a C-specimen, thereby making it possible to apply concentrated force at the weak point. Furthermore, the fatigue parameter should also be considered with changes in the loading condition. This is because previous research [2; 3; 5; 7] tends to focus on high cycle fatigue under elastic deformation. To recommend a proper fatigue parameter, fatigue life should be divided into two regions: initiation and propagation [9]. Crack initiation follows Miner's rule [10]. The rule states that, although the application of stress may not be sufficient to induce failure, the accumulation of repeating stress can lead to failure. If the damage accumulation arrives at one, then it implies crack initiation. The Stress-life (S-N) curve method is generally applied [9] to determine this cycle. This method is advantageous because measurements can be easily performed. The relationship between amplitude stress and fatigue cycle is given in Equation (1) as follows; [9]. \[\sigma_{a}=\sigma_{f}^{\prime}\times\left(2N\right)^{b} \tag{1}\]  
where \(N\) is the life cycle, \(\sigma_{a}\) is amplitude stress, \(\sigma_{f}^{\prime}\) is the fatigue strength coefficient and \(b\) is fatigue strength exponent. In addition to the fatigue curve, the mean stress effects must also be considered. The mean stress effect is a counting method for correcting non-uniform loading conditions [9].