This study sheds considerable light on the potential of superelastic shape memory alloy Belleville washers for innovative seismic resisting applications. A series of experimental studies were conducted on washers with different stack combinations under varying temperatures and loading scenarios. The washers showed satisfactory self-centring and energy dissipation capacities at room temperature, although slight degradations of the hysteretic responses accompanied by residual deformations were induced. The hysteretic loops became stable after a few number of cycles, indicating good repeatability. The washers also showed good flexibility in terms of load resistance and deformation, which could be easily varied via changes in the stack combination. Compromised self-centring responses were observed at temperatures below 0 °C or above 40 °C, and a numerical study, validated by the experimental results, was adopted to further investigate the deformation mechanism of the washers. A further phenomenological model, taking account of the degradation effects under varied temperatures, was developed to enable effective and accurate simulation of devices incorporating the washers. Good agreements were observed between the test and simulation results, and the model was shown to have good numerical robustness for wide engineering applications.
2 January 2020 in Frontiers of Structural and Civil Engineering
Fibers obtained from different parts of the oil palm tree (Elaeis guineensis) have been under investigation for possible use in construction. Studies have been carried out investigating the engineering properties and possible applications of these fibers. However, the experimental methods employed and the values of mechanical and physical properties recorded by various authors are inconsistent. It has therefore become necessary to organize information which would be useful in the design of oil palm fiber cement composites and help researchers and engineers make informed decisions in further research and application. This review provides information about fibers from different parts of the oil palm, their properties, enhancement techniques, current and potential application in cement composites.
1 October 2019 in Construction and Building Materials
This paper presents a state-of-the-art review of research on the utilization of fibers (predominantly derived from waste materials) as reinforcement in adobe brick production. Recycling of these wastes provides sustainable construction materials and helps to protect the environment. Specimen preparation and test procedures are outlined. The effects of addition of these wastes on the physical and mechanical properties of adobe bricks as presented in the literature, are investigated. The main results for each additive are presented and discussed. It is concluded that improved adobe brick properties can be expected with the addition of combination of waste additives. The use of waste materials in the construction industry is generally of interest and useful for engineers and designers seeking sustainable solutions in construction. It is also of interest to researchers actively seeking to develop methodical approaches to quantifying, optimising and testing the performance in use of such waste material additives.
29 April 2015 in Journal of Sandwich Structures & Materials
This paper presents an analytical solution for vibration and buckling of functionally graded (FG) sandwich beams using various quasi-3D theories, which consider effects of both shear and normal deformation. Sandwich beams with FG skins–homogeneous core and homogeneous skins–FG core are considered. By using the Hamilton’s principle, governing equations of motion are derived. An analytical solution is presented, and the obtained results by various quasi-3D theories are compared with each other and with the available solutions in the literature. The effects of normal strain, power-law indexes, skin–core–skin thickness and slenderness ratios on vibration and buckling behaviour of sandwich beams are investigated.