Numerical Analysis of Seepage and Deformation in Unsaturated Soils

Based on one-dimensional seepage and deformation governing equations, PDE software is used to analyze the coupled governing equations. The method is available to arbitrary functions of SWCC (soil-water characteristic curve), and it considers that both the coefficient of permeability at saturation and the porosity change with soil strain. Compared with analytical solution, the numerical solution shows high precision and it can effectively solve coupling problems. It is found that coupling effect of seepage and deformation in unsaturated soils plays an important role in the pore-water pressure profiles, and that the coupling effect should be considered during rainfall infiltration. At early stage of rainfall infiltration, settlement obviously increases with time, and the pore-water pressure considering the coupling moves more slowly than that without considering coupling due to positive H. The settlement is related with initial pore-water pressure profiles and H value. The coefficient of permeability at saturation and the porosity have an effect on rainfall infiltration and steady-state seepage, but their change has a weak influence on deformation in unsaturated soils..     

Application of Object-oriented FEM in Developing Simulation Software System

Based on object-oriented method, the classes of object-oriented finite element are defined. The finite element program of static, dynamic characteristics and stability analyses for spatial frame structures is developed with c++ object_oriented language which is successfully incorporated into a computer simulation system of derricks. The results of static, dynamic characteristics and stability analysis for the derricks of F320-A and JJ250/42-K types, obtained with the developed system, are consistent with those obtained by a commercial software, which illustrates the correctness of object-oriented FEM and the reliability of the simulation software.     

Numerical Calculation Analysis About Seepage Field of Fine Grained Tailings Pool

The initially designed deposits of the Longdu tailings pool is the mixed tailings of iron ore and covelline. However, the fact that no iron ore tailings have been infused into the pool during its employment directly influenced its stability. By making use of 2D limited meta-softwares, the authors study the seepage features of Longdu tailings pool based on the tested data and material for it. According to first dam penetration, dry slope's length and different atmosphere rainfalls, the seepage field of the tailings pool is analyzed so they can conclude seepage rules for the fine grained tailings pool under different conditions and then study the stability features of the tailings pool. The result shows that change of the deposits gives ill effect on the stability of the pool, and the tailings pool will not run normally if no proper reinforce measure is taken in time.     

Numerical Analysis of Flow and Acoustic Field Inside the Automobile Exhaust Muffler

The acoustic field,flow field and temperature field inside a muffler are studied by the numerical analyze method.And an improved design is made aiming at the existent problem.The comparison of the computationally predicted and the experimentally measured transmission loss shows a good agreement.It is indicated that the numerical analysis method can simulate the exhaust muffler's characteristic accurately.So it is an effective method to predict exhaust muffler's performance and have an improved design.     

Numerical Simulation of Groundwater Flow and Quality

With societal development, wastes exist in industry, agriculture and human life. In particular, a large volume of urban industrial sewage is discharged and pesticides and fertilizers are widely used, leading to groundwater pollution in many areas. Based on a water quality model of hydrodynamic dispersion and the multi element balance (MEB) method, a general program for simulating groundwater flow and quality is carried out using the program VC++ for visual presentation. Using this program in a case study, the transportation mechanism of groundwater flow and quality is simulated numerically. The result indicates that the program is visual and can be manipulated well. It offers a point of reference for the reasonable exploitation, protection and utilization of the groundwater.     

A Matlab Based Numerical Simulation Analysis of Shore Stress in Vacuum Plate Glass

A numerical simulation method, the node method, and single, multi-triangle progression were used to analyze the shore stress field of vacuum plate glass. By optimizing the shore distribution, the points of greatest and least stress in vacuum plate glass were determined. The distributions of greatest stress in vacuum plate glass were calculated using MATLAB. These calculations can provide numerical foundations for accurately analyzing the shore stress and flexibility of vacuum plate glass. The result shows that the greatest stress exists in the end surface of every shore, and the maximal stress is in the second shore at four-square sides, then follows the shore of next row. The theoretical calculations correspond to the software analysis results.     

Numerical Simulation of Dynamic Response of Suspension Insulator String

Finite element method is applied to analyze the windage of suspension insulator strings under dynamic wind loads. The dynamic response of a suspension insulator string of 500 kV high voltage transmission line is numerically simulated with ABAQUS software, and results demonstrate that the windage angle of suspension insulator string is larger than that calculated by the conventional design code, which might be one of the main reasons of the frequently happened windage flashover accidents.     

Failure Analysis and Ductility Optimization of CFSST Stub Column with Inner CFRP Tube Under Axial Compressive Load

In order to analyze the failure and optimize the ductility of concrete-filled square steel tubular stub column with inner CFRP tube (CFSST-CFRP) under axial compressive load, the mechanical behaviors of specimens in related tests were analyzed by a finite element software ABAQUS. And failure analysis was made. A reasonable expression on ductility optimization and improvement is drawed through nonliner regression. The results indicate that CFRP fracture is a principal reason of CFSST-CFRP stub column failure under axial compressive load. Meanwhile, its ductility can be improved by increasing the value of ξf/ξs. Concrete-filled square steel tubular (CFST) stub column crack more seriously than CFSST-CFRP, and CFSST-CFRP stub column is not functioning adequately, without available CFRP bonded.     

Numerical simulation of contact problems in high pressure reciprocating pump systems

The cylinder bodies of reciprocating pumps easily fail from cracks due to complex external loads. Based on the working principle of reciprocating pumps, hydrodynamics, and a numerical method for surface to surface contact problems, a contact model involving a cylinder body, a valve base, and a valve pocket is established. Considering pressure fluctuation, flow pulsation, alternate loads, and the impact of the inlet and outlet valves, a finite element model for the complete system is established. Using this model, the contact state of the complete system is analyzed, and the stress distribution, contact state, contact stress distribution of the interface, and position of the weak part are obtained.     

Numerical Simulation Research on Stabilityof Dissolving Cavityfor the Low-depth-thin-layer Rock Salt

In order to extend life of salt well, avoid sinking and use the formed cavity reasonably, the factors of effecton cavity stability must be researched during the process of water mining of rock salt, so that the effective prevention measures can be put. The stability of dissolving cavity for the low depth thin layer rock salt has been researched by the ADINA non linear finite element method.The results show that the stability of dissolving cavity obviously becomes strengthened with the decrease of its height, and has a decreasing trendas with the span increase of the cavity . The effect of incidence on stability of the cavity is very little. The stability of cylindroid cavity is higher than that of converse taper cavity. The assorted model is a kind of transition shape. The influencing order of cavity stability is the ffollows, height>geometrical shape>span>incidence.     

Numerical simulation of dynamic response and radiation noise of gearbox

Considering the internal dynamic excitation produced by stiffness excitation, error excitation and mesh impact excitation, a dynamic finite element model of transmission system and structure system of gearbox is established. The normal mode and the dynamic responses of gearbox under the internal dynamic excitation are calculated by using the numerical simulation software ANSYS. Based on the result of dynamic responses, the boundary excitation condition is determined, and then the acoustic boundary element model is built. With the software of SYSNOISE, the surface acoustic pressure of gearbox and the radiation noise of field points are solved by the direct boundary element method. The test of airborne noise is carried out. The computational results obtained are in a good agreement with the data of experimental test.     

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.     

Object-oriented Design of Three-Dimensional Numerical Manifold Method

The Object-Oriented technology is introduced into the 3-d Numerical Manifold method(NMM). The design method and management of the Classes about the three dimensional Numerical Manifold Method are studied. The Classes are designed and the prototypes of some key classes are shown. As an example,the 3-d numerical calculation results are given. The calculation results are in good agreement with the theoretical solutions. It shows that the Object-Oriented programming of 3-d NMM is correct.     

Numerical Simulation of Temperature Field during the Dissolution-Diffusion Bonding Process to Mending Iron Casting Defects

The common finite element method microcomputer software for simulation of the temperature field is developed by authors. It is used for calculating the temperature field duringthe mending process of iron casting defects by means of the dissolution-diffusion bonding technology. The correctness has been proved by testing results. This software has been used to analyse thecaused of hardness rising in heat effecting zone,and also find out the approach for solving the problem.     

Numerical Simulation of Berthing Velocity of the Ship

Based on the field data of berthing velocity for the ship (10000t-50000t), the berthing velocities have been numerically simulated by using Monte Carlo method in this paper. After statistical tests, it shows that the maximum values of the berthing velocity follow a Gumber distribution and the probability curves of failure for the means of maximum values are also obtained. The present results have been compared with the ones determined by specification of harbor engineering both at home and abroad.     

Numerical simulation on the seepage of tailings dam by centerline method construction

Yangla copper mine is going to build a new tailings pond for its tailings disposal. The tailings dam is 185.0 m high and centerline method is used to construct the tailings pond. For the stability of the tailings dam, 2D FLOW program is used for the numerical simulation study about the dam seepage. During simulation calculation, different conditions which include a drainage system installed into the dam or not and different beach widths, i.e. 70 (the flood condition), 100, 300 m (the normal condition), are considered. Through calculation, the change of the seepage under different conditions is obtained, which shows if the drainage system is installed into the tailings dam, the underground water can be successfully drained out. This can keep the phreatic surface level relatively low, so as to improve the stability of the dam.     

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.     

Numerical Simulation of Eelastoplastic Multi-scales Model for Casting Magnesium Alloy

To realize the transforms of stress and strain and obtain the multi-scale constitutive equation across micro/meso/macro scales.strain-stress curves for magnesium alloy(AM60) and magnesium matrix are carried out with the machine MTS.By means of mixture law,mechanical property of particle is obtained.Based on the character of magnesium alloy structure,the finite element model of unit-cell included complex micro-structures is carried out.Via finite element numerical simulation of magnesium alloy unit-cell,the methodology overcome the limitation of present analytical method.Finally the multi-scale constitutive equation has been used for the analysis of the tensile stress vs. strain curve for magnesium alloy.Results show satisfactory agreement between the stress vs strain curve by the present methodology and the experimental data for AM60.