Papers by Keyword: Parametric Analysis

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Authors: Chun Fu Jin, Peng Niu, Yong Sheng Zhao, Xuan Wang
Abstract: Combined with the finite element method (FEM) and the field data of Shenyang Metro NTR engineering for pipe jacking process, the variation of surface deformation and influence factors of NTR construction are systematically analyzed. The result is shown that the curves of the lateral surface subsidence produced by pipe jacking process are accord with the normal distribution curves put forward by Peck .When the top steel pipes are jacked , the surface subsidence develops rapidly and the rate of deformation is larger. In addition , grouting behind the wall and the sequence of the pipe jacking all have a greater impact on the deformation of the layer.
Authors: Yong Qian Zheng, Jin Ping Zhuang
Abstract: Fire resistance design of Reinforced concrete wall is one of the important issues for structural safety. The sequentially coupled thermal-stress analysis method in ABAQUS software is used to calculate the fire resistance of walls. The results of a parametric study to examine the influences of parameters, such as axial load level, lateral load level, height-to-thickness ratio, wall thickness, material strengths, steel reinforcement ratio and concrete protection thickness to reinforcements on fire resistance of RC walls are presented.
Authors: Hong Zhou, Zhan Xue Wang, Xiao Bo Zhang
Abstract: The aircraft/engine integration design numerical simulation model was established. The engine design performance specifications were obtained by calculating aircraft lift-drag characteristics, mission analysis, constraint analysis. Combining engine cycle parametric analysis with installation loss computing, the engine performance parameters can be found, which meet the aircraft flight envelope performance requirements. Taking double bypass variable cycle engine as an example to check the model, the results show that the variable cycle engine can meet aircrafts thrust and fuel consumption demands under different operating conditions, and achieve cruise thrust adjustment at the same inlet mass flow to reduce installation losses.
Authors: Xiang Yu Shang, Guo Qing Zhou
Abstract: At-rest earth pressure codfficient,K0,is very important in geotechnical engineering design and finite element analysis. At present, it’s treated as a constant usually for given soil in FEM analysis. However recent test results indicate that K0 of both clay and sand varies with pressure increasing nonlinearly. It’s shown that Duncan-Chang model, a kind of hypoelastic model widely used, can reproduce K0 varying with pressure. The calculating procedure of K0 derived from Duncan-Chang’s E-B model is proposed, and then influence of model parameters on calculated K0 is explored. Studies show that cohesionless soil’s calculated K0 decreases with pressure increasing, while cohesive soil’s calculated K0 increases with pressure increasing. Three of the seven model parameters, m, Kb and Rf, have a positive correlation with calculated K0, and there is a negative correlation between the residual parameters and calculated K0.The influence of seven model parameters on the calculated K0 decreases gradually in the following order: m ,n, Rf, φ, c, K, Kb.
Authors: Fu You Xu, X. Chen, Zhe Zhang, Cai Liang Huang
Abstract: By using FEM method, the natural frequencies of the super-long steel and CFRP cables with possible engineering parameters have been comprehensively studied. The error and limitations of cables’ natural frequencies theoretical calculation formula have also been analyzed. The results show that: Theoretical formula results are more approximate to out-plane frequencies of the cables. In a symmetric mode, out-plane frequency is lower than in-plane frequency, whereas in an asymmetric mode the situation is reversed. The difference between out and in-plane frequencies appear most in the first-order mode. The difference between out and in-plane frequencies is more obvious for cables with low stress, small inclined angle, long length with big sag and strong nonlinearities. The nonlinearities of CFRP cable is relatively slight for its lightweight and high strength. Out and in-plane frequencies are almost identical, and the theoretical formula is applicable to CFRP cables.
Authors: Nirdesh Ojha, Florian Zeller, Claas Müller, Holger Reinecke
Abstract: Characterized by excellent material properties such has high mechanical, thermal and chemical stability technical ceramics such as ZrO2, SiC, Si3N4 and AlN are increasingly being used for various applications. Traditional means of machining sintered ceramics are expensive and limited by geometry. Electrical discharge machining (EDM) is an electro-thermal machining process used to structure conductive materials. By applying a conductive layer (denoted as assisting electrode) on top of the non-conductive material, the EDM process can also be used to structure insulating ceramics. This paper presents a comparative study on the major machining parameters affecting the µEDM process of non-conductive SiC, ZrO2, Si3N4 and AlN ceramics. The influence of five major machining parameters (current, open-circuit voltage, gap voltage, duty-cycle and servo) over two responses (material removal rate (MRR) and tool wear rate) is investigated for each ceramics material. The underlying reason for the variation in the MRR among the different ceramics is examined by comparing the material properties. Melting point of the ceramics material has an effect on the MRR for the µEDM of different ceramics. The bulk resistance value of the ceramic material does not have an influence on the MRR for the µEDM of different ceramics. Scanning electron microscope (SEM) images of the cross section of the unprocessed and µEDM processed surface of these ceramics have been analyzed. The SEM micrographs show that the µEDM process does not affect the ceramics bulk. It also confirmed spalling as one of the dominant material removal mechanism for ZrO2 ceramics.
Authors: Wen Feng Du, Zhi Yong Zhou, Sheng Xiang Wang, Fu Dong Yu
Abstract: This paper deals with the issues involved during the design of a complex roof structure in the grand theater located at the city of Hangzhou, China. The complexity comes from the structural being of three reasons: long-span, complex structure and special figuration. To study the roof structure completely, researches on the mechanical properties of the structure are carried out in the paper. The nonlinear finite element method is used to analyze the geometrical nonlinear stability. Buckling and post-buckling analyses are performed to determine the load-carrying capacity of the perfect and imperfect roof structure. Meanwhile, the critical loads of the structure with different parameters are also discussed in this paper. It is shown that the effect of supporting stiffness originated from foundations and concrete structures to improve the critical load is evident. The buckling of the structure is a global collapse. With the temperature rises, the limited load-carrying capacity of the structure decreases obviously.
Authors: Tian Ji Li, Ji Ping Hao
Abstract: This paper is based on the experiment of Q460 high-strength single-angle equal-leg compression members with a concentric load at one end and normal framing eccentricity at the other end. An experimental program confirmed that the finite element software ANSYS can be used, with a reasonable degree of accuracy, to simulate the experiment and predict the behavior and bearing capacity of single-angle compression members [1]. Then, parametric analysis was done in order to examine the impacts of several factors such as initial bending, Young’s modulus of elasticity and the gusset plate thickness. It was found that initial bending and Young’s modulus of elasticity in the angle section have slight effects on bearing capacity. When the gusset plate thickness to angle width ratio is no more than 0.2, the thickness of plate has less impact on bearing capacity; when the ratio is more than 0.2, the impact increased obviously.
Authors: Ze Yu Weng, Gan Xiang, Geng Yuan Gao, Hong Gang Ding
Abstract: Performance test rig of the electric nail gun consists of five parts and the key one of which is the loading mechanism. By analyzing its working principle, virtual prototype model of the loading mechanism was established using simulation software ADAMS. Through simulation of the prototype model, the design requirements of the loading mechanism were given. Then, using the method of parametric analysis, dynamic characteristics of loading mechanism was obtained. Eventually, the relationship between the preload force of loading spring and the implanted force of the sample nail was presented.
Authors: Alžbeta Sapietová, Milan Sága, Bohuslav Hyben, Milan Sapieta
Abstract: As a result of a large number of optimising problems, the classification of these problems is essential in the analysis of a given task. One of the parameters significantly affecting the speed and effectiveness of the solution is the correct choice of the optimising variables. We start from the fact that not all the optimising variables have the same influence on the selected objective functions. The goal of the paper is to present a sensitivity analysis which will exclude optimising variables of lower influence and select parameters which will serve as design variables in subsequent optimising analysis.
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