Papers by Keyword: Energy Dissipation

Abstract: The performance of bearing has great influence on mechanical components and fatigue is one of the most important failure modes. However, the occurrence of crack is inevitable in the process of manufacture and usage. Research on characteristics of crack propagation is an important supplement and development to the traditional fatigue analysis method and test. The FE model of a bearing inner ring with a semielliptical crack is established in ABAQUS to carry out further analysis of crack propagation. The crack propagation characteristics with different initial crack size are analyzed and the energy changing law during crack propagation has been investigated under cyclic loading though FE calculation. The results provide valuable guidance for further study on fatigue crack propagation of bearings.

Abstract: Research on concrete material in many countries resulted a concrete type of Ultra High Performance Concrete (UHPC) which has a high performance in terms of compressive strength, ductility, durability, and modulus of elasticity using Reactive Powder Concrete (RPC). Research on structural engineering using RPC material shows better performance than normal concrete (NC) to resist gravity and cyclic loads. In this study, the experiments were conducted under the combination of constant axial and cyclic loads on the structure of the partial prestressed interior and exterior beam-column subassemblages with partial prestressed ratio value of 31.72% on the beam. The application of cyclic loading was conducted by displacement control based on the ACI 374.1-05. The purpose of this study was to determine the performance of structures based on three moment frame acceptance criteria presented in the ACI 374.1-05. From the test results, the interior and exterior beam-column subassemblage structure systems showed performance that adequated all of these criteria at the drift ratio of 3.50% and 2.20%, respectively.

Abstract: This paper proposes the evaluation of material coefficient of heat dissipation rate for building materials, in particular using partial entropies, a temporal change in entropy upon heating a sample of a studied material and a temporal change in entropy upon overheating a sample of a studied material, in order to evaluate the rate of heat dissipation on samples of building materials with thermal insulating properties. From a physical point of view, the material parameter “specific heat capacity” generally refers to the ability of material to “conceive heat” so it can be said that the illustrated material Ytong has a slightly higher specific heat capacity than that of polyurethane. From a physical point of view, the material parameter “thermal conductivity” generally refers to the ability of a given material to “conduct heat through the material in connection with stationary heat flux”, so it can be assumed as well as verified by measuring that Ytong also has a higher thermal conductivity than that of polyurethane. From a physical point of view, the newly proposed material parameter “heat dissipation rate” generally indicates the “rate of heat loss to the external environment in connection with non-stationary heat flux”, so it may also be assumed and verified by measuring that the heat dissipation rate of Ytong will be higher than that of polyurethane.

Abstract: Numerical studies were conducted to evaluate the behaviour of a hollow diamond shaped hysteretic steel plate damper under in-plane cyclic loading. The combine hardening material model based on Chaboche kinematic hardening rule and exponential isotropic hardening rule was proposed to trace the cyclic hardening behaviour of the steel damper. For engineering design purposes, simplified models based on bilinear and trilinear models were also presented. Numerical results showed that hysteretic curve obtained from Chaboche model and the simplified models correlate well with experimental results. Furthermore, the validity of the simplified models is verified through a comparison of its hysteretic energy dissipation with the actual test data.

Abstract: The primary functions of the spine, and in particular the intervertebral disc, are to support transfer of loads, permit motion, and dissipate energy in the spine. The objective of this study was to analyse changes in damping of a spinal motion segment subjected to cyclic loading using the energy criterion. Another important aspect of the undertaken study was an evaluation of the impact of posterior spinal column elements, i.e. articular processes joints on changes in energy dissipation by the intervertebral disc.

Abstract: A type of joint between Concrete-filled Square Steel Tube columns and steel beam is proposed in this paper, Based on joint experiment, appropriate material stress-strain relations and failure criteria are proposed, numerical simulation by finite element program is conducted under monotonic and cyclic loading and the seismic behavior of the joints under low-reversed cyclic loading is researched. Through the data contrast, it is proved that this type of joint has nice seismic behavior.

Abstract: Focusing on the green renovation project of Shendu Building in Shanghai, China, an evaluation system is developed for the comparison of a variety of seismic control schemes for seismic retrofit of the building. A three-dimensional evaluation model is developed in MATLAB to represent the dynamic features of the structural system of the building, and nine key evaluation indices are defined for the evaluation purpose from a global view of both control efficiency and costs. The complete procedure of designing control schemes based on the retrofitted benchmark structure is presented, which may be helpful for researchers and engineers in easily testing various control schemes by using this evaluation system.

Abstract: In order to study the mechanics properties to of concrete columns with embedded steel, two groups contrasting analysis models referring to SRC column and RC column are established by using finite element software ABAQUS. Both Static and cycle force are conducted. Analytical results show that bearing capacity and deformation ability of steel embedded reinforced concrete columns (SRC) under static loading are obviously higher than those of the reinforced concrete column (RC). Under the cycle force, the hysteresis circles of the SRC columns are fuller than RC column. The capability of energy consumption of the SRC columns is almost 1.4 times more than the RC columns. Further axial pressure coefficient and stirrup ratio are considered as parameters to study hysteresis characteristics, energy dissipation and the influence of the skeleton curve of SRC columns. The analytical results demonstrate that the hysteresis characteristics and energy dissipationare different with the changes of axial pressure coefficient. Meanwhile, the stirrup ratio of SRC column has little effect on energy dissipation. The study results have some value on the design and application of the SRC columns.

Abstract: In order to verify the feasibility of a new overallseismic reinforcement method of the framework. Firstly，carried low cyclic loading tests on reinforcedconcrete framework, then reinforced the framework with a new method, and repeatthe low cyclic loading tests , finally, compared and analyzed the data from twotests. Compared with the original framework, the shape of the hysteresis curveis more full and the skeleton curve of the parallel period is longer andthe ductility factor increased by 35% and the bearing capacity increased by 40%.The results show that reinforcement framework has better energy dissipationcapacity, ductility and transgender capacity.

Abstract: This paper presents a reinforcement design of five-story R/C structure with mild steel dampers in high seismic fortification intensity site. The details of the design process are listed in the paper, and the time history analyses under frequent and rare earthquake are performed on structure models with and without dampers. Through the comparison, the peak of maximum story drifts angles with damper-added structural is reduced by 38% and the distribution is more uniformly. The results show that energy-dissipation design with mild steel dampers can be a reliable and effective method in reducing seismic responses of reinforcement structure.