The numerical simulation of fatigue behavior of the Aluminum 7075-T6 cantilever beam with an angular crack has been investigated. Cracks are located separately in three different positions of the investigated beam. To predict the fatigue behavior of the cantilever beam the crack propagation was manually simulated. Compression load is applied in different stress ratios between zero and one; then, the obtained numerical results of this research are compared with the experimental results. It is observed that increasing the stress ratio increases the percentage of the fatigue life of the sample significantly. Ascending growth of fatigue life is slow and more severe by increasing of the stress ratio for the first and the third position, respectively. By increasing the stress ratio, the rate of deviation of the crack decreases and it converges to 0° in parallel to the width of the beam. This result is also observed with an increase in the distance from the support of beam. Furthermore, it is also revealed that by the increase in the initial length of the crack, the fatigue life initially reduces with smaller ratios. However, along the larger cracks, the decreasing ratio of fatigue life increases significantly.

Study of behavior of building structures under blast loads is an important issue for design of high reliable structures made of concrete material. Hence, in previous studies the enclosed wall under blast loads, open-air explosion has been investigated through experiments. In this study, the experimental results reported in the literature for dynamic performance of a masonry wall subjected to high strain dynamic loads (i.e. contact blast and air burst test) are simulated numerically using finite element method (FEM) by utilizing soft particle hydrodynamics (SPH). Comparison of simulated numerical results with the experimental data demonstrates the ability and accuracy of FEM analyses in predicting the response of confined masonry walls subjected to dynamic loads.

Various methods are available to reinforce concrete members and structures. Wrapping the concrete beams with composite sheets is one of the suggested methods for increasing the load bearing capacity of concrete beams and specially those containing opening. In this paper, the influence of using two composite sheets reinforced with carbon (CFRP) and glass (GFRP) is studied on increasing the strength of concrete beams having opening. A number of concrete beams with and without openings were modeled in ANSYS and using the nonlinear analyses, the initial cracking load, ultimate failure load, cracking pattern and deflection were determined numerically for each beam. Different wrapping schemes were examined for increasing the load bearing capacity of the opening section and it was concluded that wrapping from both inside and exterior of opening with the mentioned composite patches provide the most enhancement in the opening zone. Also the CFRP patch showed better performance in comparison with the GFRP wrapping.

A new fracture test specimen is suggested and analyzed using finite element method. The mode I and mode II stress intensity factors as well as the T-stress were calculated for three geometries and loading conditions. It is shown that the specimen, called single edge cracked ring (SECR), covers different mixed mode loading conditions from pure mode I to pure mode II. The SECR specimen also covers negative and positive values of T-stresses. From the practical view point, the suggested specimen can be used easily for mixed mode II fracture tests.