This article discusses on the behavior of unwrapped and GFRP (Glass fiber reinforced polymer) wrapped hollow circular steel tubes under AXIAL and eccentric COMPRESSION (25 mm and 50mm). Finite element analyses through ANSYS were carried out on similar specimens. Comparisons of results proved that GFRP jacketing is an effective method for arresting elephant foot buckling in hollow steel tubes under both loading conditions. It also enhanced the stiffness, ultimate load and ductility of unwrapped tubes. More than two number of GFRP layers showed unfavorable inward buckling of tubes. Effective confinement was achieved by restricting the number of wrapped layers to two.

As a typical buffer energy absorbing structure, thin-walled tube filled with foam aluminum has good mechanical properties and energy absorption characteristics. Therefore, the AXIAL COMPRESSION performance of square tube and foam aluminum filled square tube was experimentally studied by quasi-static mechanical loading method. On the basis of the existing experimental research and theoretical analysis, the strain rate is introduced into the dynamic COMPRESSION theory, and the mathematical model of the average crushing load of foam aluminum filled square tube under the AXIAL quasi-static and impact loads is obtained. By comparing the theoretical results with the simulation results, the relative error of quasi-static and impact state is 2.8% and 8% respectively. This paper not only proves that foam aluminum filling can significantly improve the bearing capacity and energy absorption performance of square tube structure in the AXIAL COMPRESSION process, but also provides a more specific theoretical basis for the AXIAL COMPRESSION energy absorption design of square tube filled with foam aluminum.

This paper presents the results of Adaptive Neuro-Fuzzy Inference System (ANFIS) based model for Reinforced circular columns strengthened with Carbon fibre reinforced polymer (CFRP) sheets. The main objective of this paper is to propose ANFIS based model for predicting the performance characteristics of CFRP strengthened RC columns and to compare it with the experimental results. ANFIS uses neural network for computing the numerical results of functions and fuzzy logic for making decisions based on the resulting values. The ANFIS predicted results show good agreement with the experimental test results.

The buckling analysis of stiffened cylindrical shells by rings and stringers made of functionally graded materials subjected to AXIAL COMPRESSION loading is presented. It is assumed that the material properties vary as a power form of the thickness coordinate variable. The fundamental relations, the equilibrium and stability equations are derived using the first order shear deformation theory. Resulting equations are employed to obtain the critical buckling loads. The effects of the material properties and geometry of shell on the critical buckling loads are examined. Excellent agreement with the results in the literature indicates the correctness of the proposed closed form solution.

In this experimental study the strength and behaviour of plain and fibre reinforced Geopolymer concrete (GPC) columns under repeated AXIAL COMPRESSION were evaluated. A total of fifteen GPC square columns of size 150 mm and length 900 mm were cast and tested to evaluate the performance. The main variable considered in this study is the volume fraction of fibres such as 0.25% (19.62 kg/m3), 0.5% (39.24 kg/m3), 0.75% (58.86 kg/m3) and 1% (78.48 kg/m3). Experimental results revealed that addition of steel fibres slightly improved the AXIAL strength and significantly improved the stress-strain behaviour and ductility of columns. For a better understanding of the stress and strain behaviour of column a finite element model for both plain and fibre reinforced GPC column was developed using standard finite element software (ANSYS 11.) and was found to compare satisfactorily with the experimental results.