Nonlinear Finite Element Analysis of a FRP-Strengthened Reinforced Concrete Bridge

Three-dimensional nonlinear finite element (FE) models are developed to examine the structural behavior of the Horsetail Creek Bridge strengthened by fiber-reinforced polymers (FRPs). A sensitivity study is performed varying bridge geometry, precracking load, strength of concrete, and stiffness of the soil foundation to establish a FE model that best represents the actual bridge. Truck loadings are applied to the FE bridge model at different locations, as in an actual bridge test. Comparisons between FE model predictions and field data are made in terms of strains in the beams for various truck load locations. It is found that all the parameters examined can potentially influence the bridge response and are needed for selection of the optimal model which predicts the magnitudes and trends in the strains accurately. Then, using the optimal model, performance evaluation of the bridge based on scaled truck and mass-proportional loadings is conducted. Each loading type is gradually increased until failure occurs. Structural responses are compared for strengthened and unstrengthened bridge models to evaluate the FRP retrofit. The models predict a significant improvement in structural performance due to the FRP retrofit.     

平整机辊系变形的有限元分析

通过对辊系变形的模拟,分析了轧制条件下对工作辊弯曲变形、支撑辊弯曲变形及接触应力的影响,借助大型有限元分析软件ANSYS的手段,对辊系进行了弹性力学结构分析,得出了在轧制过程中辊系的变形情况及载荷分布等详细直观的分析结果。     

有限元法在加热炉基础温度场分析中的应用

在加热炉基础的设计过程中，常常不能确定基础所处的温度，本文用有限元法并借助有限元分析软件（ANSYS）对几种不同特点、不同尺寸的基础建立有限元分析模型，并加载不同的边界奈件，从而对加热炉基础的温度场进行了分析，根据计算结果，找出加热炉基础温度场中的一些特点，为基础的设计优化提供依据。     

Determining the Tensile Stress-Crack Opening Curve of Concrete by Inverse Analysis

The determination of the fundamental stress versus crack opening (σ-w) response of concrete under uniaxial tension is performed in this study through inverse analysis using data from notched beam tests. The procedure used for optimizing the parameters of the σ-w relation using the load versus crack mouth opening displacement response of the notched beam is described. Satisfactory comparisons have been obtained between the σ-w curves obtained through the inverse analysis and those directly measured in uniaxial tension tests. The use of weighting functions in the inverse analysis may be necessary when large crack widths are to be considered.     

Finite Element Response Sensitivity Analysis of Steel-Concrete Composite Beams with Deformable Shear Connection

The behavior of steel-concrete composite beams is strongly influenced by the type of shear connection between the steel beam and the concrete slab. For accurate analytical predictions, the structural model must account for the interlayer slip between these two components. In numerous engineering applications (e.g., in the fields of structural optimization, structural reliability analysis, and finite element model updating), accurate response sensitivity calculations are needed as much as the corresponding response simulation results. This paper focuses on a procedure for response sensitivity analysis of steel-concrete composite structures using displacement-based locking-free frame elements including deformable shear connection with fiber discretization of the cross section. Realistic cyclic uniaxial constitutive laws are adopted for the steel and concrete materials as well as for the shear connection. The finite element response sensitivity analysis is performed according to the direct differentiation method. The concrete and shear connection material models as well as the static condensation procedure at the element level are extended for response sensitivity computations. Two steel-concrete composite structures for which experimental test results are available in the literature are used as realistic testbeds for response and response sensitivity analysis. These benchmark structures consist of a nonsymmetric, two-span continuous beam subjected to monotonic loading and a frame subassemblage under cyclic loading. The new analytical derivations for response sensitivity calculations and their computer implementation are validated through forward finite difference analysis based on the two benchmark examples considered. Selected sensitivity analysis results are shown for validation purposes and for quantifying the effect and relative importance of the various material parameters in regards to the nonlinear monotonic and cyclic response of the testbed structures.     

翻车机转子的有限元分析

运用Solid works&COSMOS有限元分析软件,建立翻车机转子有限元模型并进行分析,计算了翻车机转子的应力分布状况,并进行静强度校核,找出了翻车机转子出现结构变形的原因.     

热矿振动筛筛箱故障有限元分析和改进

应用有限元分析软件ANSYS对安钢烧结厂SRZ3175型热矿振动筛筛箱侧板上产生的裂纹,进行了静力学分析和动力学分析,重点研究了该裂纹形成的机理,并提出了改进措施,对改进后的筛箱结构重新进行的有限元分析结果表明,改进取得了明显效果。     

Application of Graded Finite Elements for Asphalt Pavements

Asphalt paving layers, particularly the surface course, exhibit vertically graded material properties. This grading is caused primarily by temperature gradients and aging related stiffness gradients. Most conventional existing analysis models do not directly account for the continuous grading of properties in flexible pavement layers. As a result, conventional analysis methods may lead to inaccurate prediction of pavement responses and distress under traffic and environmental loading. In this paper, a theoretical formulation for the graded finite element method is provided followed by an implementation using the user material subroutine (UMAT) capability of the finite element software ABAQUS. Numerical examples using the UMAT are provided to illustrate the benefits of using graded elements in pavement analysis.     

板坯连铸机弯曲段有限元分析

根据CAD二维设计图,在INVENTER中建板坯连铸机弯曲段的三维实体几何模型,再将该几何模型导入有限元分析软件ABAQUS中完成有限元建模,在此基础上完成弯曲段有限元分析。分别计算和比较了原始设计方案和四种优化方案下弯曲段的位移和应力,计算结果为板坯连铸机弯曲段的设计提供了依据和参考。     

出口日本300t钢水包有限元仿真分析

在 SGI工作站上运用 I-DEAS软件对 3 0 0 t钢水包进行有限元仿真分析 ,经过建模、加载、约束及分析计算 ,得出了钢水包在三种不同工作状况下的变形及应力情况 ,并利用后处理模块对结果进行了分析研究。不仅为产品的设计定型提供了可靠依据 ,而且该钢水包的设计成功对国内冶金行业偏于保守的设计思想也是一个很大的启发。     

Latin Hypercube Sampling for Stochastic Finite Element Analysis

A Latin hypercube sampling method, including a reduction of spurious correlation in input data, is suggested for stochastic finite element analysis. This sampling procedure strongly improves the representation of stochastic design parameters compared to a standard Monte Carlo sampling. As the correlation control requires the number of realizations to be larger than the number of stochastic variables in the problem, a principal component analysis is employed to reduce the number of stochastic variables. In many cases, this considerably relaxes the restriction on the number of realizations. The method presented offers the same general applicability as the standard Monte Carlo sampling method but is superior in computational efficiency.     

4200mm轧机机架的三维有限元分析

本文应用ＳＡＰ５Ｐ程序，在微机上完成了４２００ｍｍ轧机机架的有限元分析，对我国自行设计制造的第一台大型轧机的技术改造提供了可靠技术参数，并对轧机减小危险点应力，提高安全系数的可能性，进行了充分的讨论。     

Three-Dimensional Finite Element Analysis of Underground Caverns

Detailed performance monitoring studies have been carried out for determining the deformations and stress distribution around underground powerhouse caverns in nonhomogeneous rock mass, using three-dimensional finite element method. The behavior of rock mass has been analyzed by elasto-plastic model. The effect of weak zones and creation of multiple caverns in the rock mass has been investigated. The deformations predicted in the surrounding area of the caverns are compared with those obtained by multi-point borehole extensometers (MPBX) measurements. It is observed that the computed deformations compare reasonably well with the MPBX measurements.     

曲柄连杆式飞剪机机架的有限元分析

针对某厂２５ｔ曲柄连杆式飞剪机使用中存在的问题,根据掌握的国内外资料,编出了飞剪四连杆机构运动分析和动力分析的ＦＯＲＴＲＡＮ程序,并采用ＡＬＧＯＲ软件对飞剪机机架进行了有限元分析和强度研究,得出了飞剪机架的应力、应变分布,找出了薄弱环节,并应用电阻应变仪在现场作了多点测试,其理论值与实测值较好吻合。对飞剪机架提出了改进措施,并对改进后的机架进行了有限元分析。     

无横梁高刚度轧机机架有限元分析

利用有限元法对２５０ 无横梁高刚度轧机机架强度、刚度进行分析，从中找出机架的薄弱环节，为机架的设计制造提供理论依据。     

转炉副枪主轴的有限元分析与研究

以转炉副枪主轴为研究对象,对其进行理论分析,并建立有限元模型。在此基础上用ANSYS软件对主轴进行结构静力分析,得到主轴在各旋转角度下的应力应变分布云图。通过分析应力云图的分布规律,设计了一种更为合理的限制主轴转动的结构形式,有效减少应力集中及主轴最大综合应力值,为后续主轴的优化设计提供了基础。     

轧机闭式机架的有限元分析及优化设计

利用ANSYS软件对轧机闭式机架进行三维有限元分析的基础上 ,以轧机机架纵向刚度最大为追求目标 ,在ANSYS软件中对其主要参数进行了优化。根据提出的优化模型及方法 ,即可确定机架主要尺寸 ,并可以得出每个尺寸对机架刚度的影响。     

解体式钢水罐回转台螺栓强度有限元分析

采用Inventor三维建模软件建立了某360t解体式钢水罐回转台三维实体模型,利用ABAQUS有限元软件对连接座与回转支撑台之间的连接螺栓和底座与基础之间的地脚螺栓进行了有限元静力分析。通过对连接螺栓和地脚螺栓在施加螺栓预紧力和不施加预紧力的情况下局部区域的精细分析,给出了两种状态下螺栓连接区域的应力分布和变形,得到螺栓预紧力足够的结论,同时指出不施加螺栓预紧力会导致连接区域的分离,这在工程中是不容许的。     

3D Finite Element Study on Load Transfer at Doweled Joints in Flat and Curled Rigid Pavements

This study examines load transfer across doweled joints in rigid pavements using 3D finite element analysis. A recently developed dowel modeling strategy is employed that allows the efficient and rigorous consideration of dowel/slab interaction. Parametric studies on the response of a typical, dowel‐retrofitted pavement system subjected to axle loads and varying degrees of slab curling are conducted. To examine the effect of slab support on pavement response, the studies consider two different foundation types: layered elastic with an asphalt‐treated base and a dense liquid foundation. The results of the studies are discussed with emphasis on the effect of slab curling and foundation type on joint load transfer and the potential for joint distress. While there are significant differences in response for the ATB‐supported slabs and the slabs founded on a dense liquid, slab curling does generally increase dowel shears and dowel/slab bearing stresses. However, further examination of the parametric study results that accounts for compressive fatigue of the concrete at the dowel/slab interface indicates that slab curling may not significantly increase the potential for damage to the slab concrete surrounding the dowels.     

步进梁式加热炉炉底机械滚轮接触应力有限元分析

在ABAQUS有限元分析软件建立了炉底机械滚轮接触的三维几何模型,并采用弹塑性理论、网格自适应加密技术及显示求解的方法,对炉底机械的滚轮和轨道进行了弹塑性接触应力有限元分析,得到了大量的轮轨接触力、接触状态和轮轨应力的数据,为步进梁式加热炉炉底机械的优化设计提供理论依据。