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In this paper, ratcheting behavior of stainless steel 304L cylindrical shells under cyclic combined and axial loadings are studied, experimentally. Tests were performed by a servo-hydraulic INSTRON 8802 machine and the shells were fixed normal and oblique under 20 degree and subjected to cyclic loads. In this paper, the effect of length of cylindrical shell and the effect of angle of cylindrical shell on ratcheting behavior were investigated. Based on the experimental results, it was found that bending moment plays a crucial role in waste of energy and increase in plastic deformations. Seen that due to the existence of bending moment in different cross section of oblique cylindrical shell, there are more plastic deformation and accumulation in comparison to normal cylindrical shell. Also, analyzing the loading history of cylindrical shell under combined loading, it has been seen that by keeping the mean force at constant value while increasing the force amplitude, the ratcheting displacement became higher and by the prior load with higher force amplitude retards the ratcheting behavior and plastic deformation with samller force amplitude.

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In this paper, buckling and energy absorption behavior of stainless steel semi-sphere, cylindrical and conical shells under axial loading are studied. Every shell with the same mass and different shapes with and without groove is designed. In this paper the effect of shape, thickness, height, groove of shells and distance between grooves, on buckling and energy absorption were investigated. In experimental test, Samples had same mass and thickness and also grooves had same depth and distance. Experimental tests were performed by a servo-hydraulic INSTRON 8802 machine. Numerical analysis is carried out by ABAQUS software and is validated with experimental results.