TY - JOUR T1 - Calculation of static and dynamic stress intensity factors in orthotropic functionally graded materials using displacement correlation technique TT - محاسبه ضرایب شدت تنش استاتیکی و دینامیکی در مواد تابعی ارتوتروپیک با روش جابجایی JF - mdrsjrns JO - mdrsjrns VL - 16 IS - 3 UR - http://mme.modares.ac.ir/article-15-9841-en.html Y1 - 2016 SP - 79 EP - 86 KW - Stress intensity factors KW - Functionally Graded Materials KW - Displacement correlation technique KW - Non- homogeneity parameter KW - finite element method N2 - Static and dynamic stress intensity factors are important parameters in the fracture behavior of the cracked bodies. In the present study the displacement correlation technique (DCT) is presented to calculate static and dynamic stress intensity factors of functionally graded materials (FGMs). The displacement field is obtained using finite element method (FEM) and ABAQUS software. To consider the variation of material properties, a subroutine is prepared in the UMAT subroutine of the software. Eight-node singularity elements are used in the FEM. As ABAQUS software is not able to calculate stress intensity factors of FGMs, so a MATLAB code is developed to obtain these factors. By analyzing an example under dynamic load, dynamic fracture behavior of orthotropic FGMs and effect of non-homogeneity parameter are investigated for two cases of material properties variation directions which are perpendicular to each other. To verify presented method, a center crack in a plate of homogeneous and FGM materials are analyzed under static and dynamic loads, the results are compared with data of literatures. The results show that, if the material properties vary parallel to the crack direction, the mode I dynamic stress intensity factor at the crack tip located in the stiffer part increases with increasing of non-homogeneity parameter, while for variation in the normal direction to the crack, this factor first increases and then decreases. M3 ER -