1. Abstract This paper focuses on improvement of the crashworthiness of tubular structures using compliant mechanism approach to intelligently tailor local mechanical properties throughout the structure. The ideal crashworthy performance for energy absorbing tubular structures can be achieved by promoting progressive buckling throughout the length of the tube to occur. Progressive buckling is t...

Elastic liners are used for in situ repair and retrofitting of pipes as a cost effective alternative to the replacement of damaged parts and sections. In this paper, we studied the role of an elastic liner on the buckling behavior of a cracked cylindrical shell using finite element method. A special meshing scheme that could mimic the stress singularity at the crack tip was employed to model th...

Owing to their remarkable mechanical properties, carbon nanotubes have been employed in many diverse areas of applications. However, similar to any of the many man-made materials used today, carbon nanotubes (CNTs) are also susceptible to various kinds of defects. Understanding the effect of defects on the mechanical properties and behavior of CNTs is essential in the design of nanotube-based d...

A series of tests on cold-formed steel foamed concrete (CSFC) composite walls subjected to axial load were proposed. The primary purpose of the experiments was to study the mechanical behavior and identify the failure modes of CSFC composite walls. Two main factors were considered in this study: 1) specimen with pouring foamed concrete or without and 2) different foamed concrete density ranks (...

In this paper, buckling of cylindrical grooved shells under axial load has been examined by theoretical and experimental methods. The shell is made of USA/API – X42 5L steel standards. This material is one of the most common materials used in gas, oil and petrochemical industries. The effect of spiral grooves on cylindrical shell was analyzed, and the results obtained from the Abaqus software w...

An optimal design of internal pressurized stiffened conical shell is investigated using the genetic algorithm (GA) to minimize the structural weight and to prevent various types of stress and buckling failures. Axial compressive load is applied to the shell. Five stress and buckling failures as constraints are taken into account. Using the discrete elements method as well as the energy method, ...

in this article, thermal stability of beams made of functionally graded material (fgm) is considered. the derivations of equations are based on the one-dimensional theory of elasticity. the material properties vary continuously through the thickness direction. tanigawa's model for the variation of poisson's ratio, the modulus of shear stress, and the coefcient of thermal expansion is...

Several deficient steel structural members require to be strengthened all over the world. In this article, horizontal defects were generated at three locations (top, middle, and bottom) on the middle element and the middle of the side element. Consequently, the effects of the location of such defects on axial behavior of Carbon Fiber Reinforced Polymer (CFRP) strengthened steel Square Hollow Se...

Abstract Owing to their unique material design-ability and excellent weight reduction properties of carbon fibre reinforced polymers(CFRP), commercial aircraft OEMs have been innovating design manufacturing approaches wider the application advanced composites. In this paper, bearing capacity composite hat-stiffened panels is determined by an improved engineering calculation method numerical ana...