In the central hole drilling method, the calibration factors relate the released strains to the residual stresses. In order to calculate the residual stresses for isotropic materials, two calibration factors from released strains are enough. However, for composite materials nine calibration factors are needed. These factors are presented in a matrix format and determining them for orthotropic materials is a tedious task. In this article, a new method for calculating the calibration factors for measuring the residual stresses in different material systems is presented. The simulated hole drilling method can be used instead of experimental techniques. In this method the process of hole drilling, using a finite element method, is simulated. The drilling location is simulated by a finite element technique and after applying the initial load in the form of residual stresses, the elements in the hole area are deleted from the model. Then, the strain around the hole area under the strain gages are calculated. The two and three dimensional simulations of the hole drilling method for isotropic materials are presented. The calibration factors are calculated and compared with those available in the standards. The results show a difference about 0.3% between the two methods. The simulation of the hole drilling process for the orthotropic materials, by different Poisson’s ratio, different shear stiffness and different module of elasticity is performed. For orthotropic materials, using the method presented in this study, the calibration coefficient matrix is obtained. The results are compared with the available analytical results. The consistency of the results show the reliability of the modeling process presented in this research. Also for laminated composite materials the presented method is utilized and the calibration coefficient matrix is obtained. Different laminated composites with various lay ups and materials are considered. Using the simulated hole drilling method and calculating the residual strains around the hole area and calculating the calibration coefficient matrix, the residual stresses due to curing process are calculated. In this study different laminated composites are simulated and by finding the calibration coefficient matrix, the residual stresses are obtained. The results are compared with the available experimental data and a very good correlation is obtained. The main advantage of the presented method is the capability to simulate the residual stresses in orthotropic materials with any degree of orthotropy. This method is able to simulate the behavior of different strain gages with different sizes and hole diameters. Simulation of the residual stresses for components and parts with complicated geometry is an application of this method. For very small components where measurement by with experimental methods is not possible, the SCHD method can calculate the calibration factors and therefore the residual stresses can be obtained. The calculation of the residual stresses in complicated specimens is another capability of the method presented in this study. Also, if the gradient of the variation of the residual stresses is too high, the SCHD method is a suitable method to measure the residual stresses. Moreover, this method can be used to measure the calibration factors for calculation of non-uniform stresses through the thickness of the thick components.
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