Finite Element Reliability Analysis of the Stability of a Slope

The whole reliability index of a slope is derived through using the strength reduction method in the finite element analysis, which can make use of the former finite element program and can be used to both linear and nonlinear finite element analysis. The affection of the evaluation of derivative and the selection of reliability analysis methods is discussed, which shows that it is very important to select the type of limit state function of the slope stability. A new iterafive formula, which can consider the correlation of fundamental parameters, is proposed for FORM, and the convergence is very well.     

The Elastic-Plastic Analysis of Collinear JointsLoaded by Shearing-Compressive Stresses

In this paper the problem of collinear multi-joint in rockmass loaded by shearing-compressive stresses is simplified as that of a joint in finite rockmass. The basic equations with Mohr-Coulomb criterion are solved by the line field analysis method near the joint line in an elastic-perfectly plastic materials. Through a reasonable boundary condition on the joint surface and matching conditions at the elastic-plastic boundary, the relation between length of the plastic region on the joint line and the shearing-compressive stresses is obtained. The failure laws of the rockmass contained collinear joints are also obtained.     

Numerical Analysis on Stability of Rock in Sijiaotian Tunnel

The Sijiaotian Tunnel in Yunnan Dabao Highway lies in the narrow defile landscape,and the engineering geology condition is complex,with plenty of cienega.According to the actual situation of the Sijiaotian Tunnel Project in Yunnan Dabao Highway,the stability of the surrounding rock mass is studied by using a 3-D non-linear FEM.The Drucker-Prager criterion is chosen as the failure criterion of the rock.The relatively dangerous zone and the monitoring points in the tunnel are determined.The numerical results show that the Sijiaotian Tunnel is relatively stable.The conclusion has some significance for guiding the construction of similar projects.     

The Recent Progress of the Slope Stability Analysis Methods

The slope stability is an important research content in rock mechanics. In recent years, the great achievement has been gained for the slope stability analysis methods. The deterministic analysis methods, including limit equilibrium theory, numerical analysis method, graphic method and compound method, have been developed. The stochastic analysis method and the fuzzy analysis method come forward. The recent progress of the slope stability analysis methods is analyzed in this paper. The trend of progress of the slope stability is studied.     

Elastic Analysis of Beam-Plate Foundation with Winkler Model

The beam-plate foundation is divided into two parts.The boundary element methods areapplied to analyze the plates with Winklermodel.The finite element methods are used to evaluate thebeams The coupling equation is obtained by the coodination of both force and displacement.     

Analysis on the Quasi Monte-Carlo Method and its Application in the Slope Reliability

The critical reliability slip surface with minimum value of reliability index is difficult to be obtained by the Monte-Carlo method. The simplified Bishop method was adopted to calculate the factor of safety for given circular slip surface thereby defining the performance function in reliability analysis. Six variance values of random variables were designed and four sample ranges were assumed. A quasi-Monte Carlo method was defined with fow samples. One hundred and thirty-two potential slip surfaces were randomly generated. The reliability indexes regarding those slip surfaces were calculated by Monte-Carlo method and quasi-Monte Carlo method, respectively. The comparative results show that in the case of one random variable, the reliability index from Monte Carlo method is found to be linear with that from quasi-Monte Carlo method. In the similar conditions, the wider the sample range, the smaller the tangent value of line, and Vice versa. In addition, the bigger the sample number, the bigger the tangent value of line. The Quasi-Monte Carlo method is approved to be practicable for the determination of critical reliability slip surface for homogeneous slope.     

The Application of Extrapolation of FEM to the Eigen Value Problems of Waveguide

On the basis of the method of linear finite element and taking the advantage of the theory of finite element extrapolation,the paper discusses the method for calculating the eigenvalue of waveguide.The results show the method is simple and has higher accuracy.     

The simulation of conducted EMI in the ignition system for automotives

The ignition system in automobiles is a main source of electromagnetic interference (EMI), because the electromagnetic emission from the system has the characteristics of high-energy and wide-bandwidth. A method for EMI prediction based on its components’ circuit models is presented. First, the characteristics of the components are analyzed and the equivalent circuits are drew; then, the parasitic parameters of the electromagnetic device are extracted from measurement, analytical solution or finite element method (FEM); and finally, the circuit model of the whole ignition system model in high frequency condition is established. This model is verified by the measurement and simulation results in time domain and in frequency domain.     

Construction and Confirmation of a Model for Time Dependent Resistance of the Steel Structure Project

We developed a model of time dependent resistance for a steel structure project and discuss herein the expression and the primary value of many parameters in the model. On the basis of the APDL language furnished by universal finite element program, we united the functions of structural and statistic analyses. A time dependent reliability analysis was implemented. The result of the time dependent reliability analysis was compared with that of the no time dependent reliability analysis. Through testing a calculated example, we saw that when the time dependent resistance was considered, the factor of time greatly influences structural reliability. In addition, we found that the model of time dependent resistance for a steel structure is reasonable and feasible.     

Nonlinear Finite Element Analysis for Seismic Performance of High - Strength Concrete Beam -Column Joints with New Reinforcement Details

Because the factors that affect the behavior of the beam-column joints are complicated,an experimental study alone is not sufficient.Therefore,a nonlinear finite element analysis was conducted to provide better understanding of the performance of the beam-column joints.The authors intend to do the parameter study with nonlinear finite element method after a lot of high-strength concrete beam-column joints have been experimented.In this paper,the analytical model firstly was applied to simulate the experimental joint behavior and the comparison results were very well.Based on this,the parametric analysis of concrete strength on seismic performance of beam-column joints has been conducted.     

A Three Dimensional Simplified Method for Analysis of Soil Arching Effect in the Pile-supported Embankments

To improve the understanding of the soil aching effect in the embankment fill, a series of model tests and finite element analysis were carried out. It is found that for low fill height relative to the net pile spacing, H/s－a≤1, the failure surface is vertical or slightly inclined which starts from the pile edge and goes through the whole fill height. For H/s－a≥1.5, the developed bulb shaped rupture surface is located near the pile head and can be approximated as a logarithmic spiral surface. By using the failure surface shape determined from the model test and FEM analyses, a three dimensional simplified method to evaluate the soil arching effect was proposed. The computed results were compared with FEM results and the experimental data collected from literatures, it is found that the present simplified method can predict reliable results.     

FEM analysis on the earth pressure behind the panel of post-panel retaining wall

the distribution of earth pressure behind the panel of post-panel retaining wall is analyzed with 3-D FEM. Eight-crunode isoparametric element is adopted, concrete is regarded as linear elastic object, soil is regarded as elastic-plastic object, an interface model is introduced to simulate the interaction between concrete and soil.It is demonstrated that the earth pressure behind the panel of post-panel retaining wall is greatly different from the classical earth pressure theory, its distribution is close to a parabola. Based on FEM analysis, a modified formula is induced to calculate the earth pressure behind the panel of post-panel retaining wall, the engineering design by this modified formula will be more economical and reasonable.     

Study on Analysis Methods for Rock Slope FoundationStability of the Highrise Building

Based on the practical project a study on analysis methods for rock slope foundation stability of highrise-building project criterion transfer coefficient method, rotation limit equilibrium method (Sweden slices method) and finite element method was carried out.The authors found that safety factor of criterion transfer coefficient method is larger than that of rotation limit equilibrium method, but is similar to the results of finite element method. So, when rockslope foundation stability of highrise building is to be analysed,the rotation limit equilibrium method is suggested to use.     

Experimental Analysis on Seismic Performance of Steel Bracing Bound-Column Component

The seismic resistant performance and failure mechanism of the steel bracing Bound-Column were analyzed with tests and the finite element method. Two-story steel bracing Bound-Column test specimen was selected. The braces adopt long leg back-back double angle. Tests were divided into three groups, including one monotonic loading test and two cyclic tests. Lateral load-bearing capacity, stiffness and hysteretic behavior of the steel bracing Bound-Column were obtained by the comparison of test results and the finite element method. Results show that the steel brace of Bound-Column contributes a lot to its load capacity and stiffness, while the external frame provides little lateral rigidity and capacity. Bound-Column failure occurs only in the steel braces, while the external frame is with no damage.     

Finite Element Analysis of the Influence of Steel Strength on Beam-to-column Composite Connections

Because high material strength and composite load-bearing are emphasized in constructing members for high-rise steel frame structures, in a composite connection, steel strength has a dramatic influence on both the bearing performance and the composite action of the concrete slab. Based on a finite element analysis, we discuss the composite effect and the connection breaking mode, focusing on the performance change of the composite effect in adopting high strength steel. It can be found from the results that, along with the improvement of the steel strength, the elastic and plastic ultimate strength of the composite connection will increase, the ductility will decrease to a certain extent, and the composite effect of the concrete slab will diminish. The collapse of the concrete in a positive moment side contacting the column flange is viewed as the limiting state of the connection.     

Experiment and FEM Analysis on the Joint of Inserted Steel Beam

A new composite structure which is composed of steel beam and concrete girder is introduced in fuel electric plant construction. With different height of concrete girders with or without anchor bar, two scale models from an actual project were designed and tested. It is shown that the maximum restraining moment of ends of steel beams is approximately 60kN*m; influence of anchor bar is little; the one with 600mm high concrete beam is damaged by shear, and the others steel beam is damaged by bending failure. Finite element models were built for supplementary analysis, and the result indicates that critical value of the height of concrete beam of different failure modes is 700mm; stiffness of shear key and thickness of floor have great influence on the structure; size of anchor bar has little influence; and width of the end of the steel beam has certain influence.     

Analysis of spatial electric field with point-plateelectrodes configuration using finite element method

To investigate the spatial electric field with the point-plate electrodes configuration, variations of the electric field intensity are analyzed for absolute air dielectric and liquid dielectrics contained in air dielectric based on the finite element method of numeric computation. The results show that the electric field intensity of the spatial electric field is great non-uniform with the point-plate electrodes configuration for absolute air dielectric, and it can be increased rapidly at the nozzle point to achieve a maximum value. Single oil drop existed in air dielectric induces a biggish deformation of the gradient of the electric field intensity in its neighbor field. Many oil drops along with horizontal distribution have an obvious tensioning operation on the electric field, so the electric field intensity on the normal at the nozzle point has an evident augment for overlapping effects among the oil drops, and it can spread electric corona area of the total spatial electric field.     

Experimental Study on Mechanical Behavior of Y-Shaped Transfer Joint Used in Obliquely Crossing Lattice

In order to study the mechanical behavior of the Y-shaped joints in oblique crossing lattice, two 1:3 scale models of the Y-shaped joints which are respectively applied symmetrical and asymmetrical axial force in experiment processes are tested, and the corresponding numerical simulations are carried out by using ABAQUS software. The stress state and deformation behavior of concrete-filled square tube column and steel beam rigid joint with internal diaphragms for high-rise structure are analyzed. The results of the test and the numerical simulation consistently show that in the loading process, the deflection of the joint core is insignificant and a good connection, the joint core is able to deliver the internal force effectively before the damage of the oblique column and meet the requirement of “strong joint and weak column”.     

Force Analysis on Meshing Surface and Stress Research of the Cone Roller Enveloping Worm Gearing Transmission

By using the finite element elastic contact analysis method combined with the I-DEAS engineering analysis software, this paper studies the strength of the cone roller enveloping worm gearing,which is a new type of worm gearing transmission,on SUN-4 working station. It also analyzes loading distribution among meshing gears, the contact force distribution along the contact line ,the bending stress distribution and the contact stress distribution of the cone roller enveloping worm gearing with three-tooth meshing instantaneously. Besides,it provides the theoretic basis in the further researches for the new type of worm gearing transmission.