Finite Element Model Of Frame Research Articles

Working mechanism evaluations of full-scale joints with bolted-cover plate connection for modular steel buildings

The force-reliability of the modular structural joints is crucial for ensuring the structural integrity of modular steel buildings. However, the welds connecting the beam and column within the module are susceptible to tear during seismic events. This mode of failure greatly undermines the ability of these joints to withstand seismic forces. Four full-scale modular structural joints with bolted-cover plate connection were designed and conducted for seismic performance testing, emphasizing the significance of methods such as reinforcing diagonal braces and strengthening flanges on the protective effect of beam–column welds in the module. The simplified modular structural joint and frame finite element model were proposed based on experimental data, refined finite element modeling, and theoretical analysis. The findings suggest that the seismic behavior of the modular structural joint remains unaffected by variations in axial compression ratio within the designed range of parameters. The beam–column weld of the module in the reinforced joint exhibits almost no weld tearing, and both strengthening methods demonstrate exceptional capacity for energy dissipation. The proposed simplified modeling method facilitates the efficient determination of the modular structural joint bearing capacity and the lateral stiffness of the modular frame. The research findings presented in this paper can serve as a valuable reference point for the engineering design of modular steel structures.

Seismic response of a steel frame considering the underground subway-soft soil-steel frame interaction

The existence of the underground structures can alter the mechanical behavior of surface structures, leading to increased damage during earthquakes. Therefore, it is essential to consider the effects of underground structures. This paper presents a modeling method for soft soil-steel frame structures, with results that are well-correlated with test data, providing a reliable foundation for modeling the entire system. The subway station is introduced, and the underground subway-soft soil-steel frame finite element model is established to study the influence of soft soil and underground subway on the seismic response of the surface steel frame. Key parameters, including soil stiffness, surface structure, earthquake type, and horizontal distance between the underground and surface structures, are taken into consideration. The results show that soft soil has the ability to filter and amplify seismic waves, and its impact on the soil surface varies depending on the specific seismic wave and soil stiffness. Lower soil stiffness leads to a more pronounced amplification effect. Additionally, the presence of an underground subway can scatter and reflect seismic waves, resulting in a 10 % or so increase in peak acceleration at the soil surface under the same ground motion excitation. Finally, the maximum inter-story drift ratio of the steel frame structure increases significantly under the excitation of EL-Centro and Kobe waves, whereas its change under the Taft wave excitation depends on specific parameters.

Structural Design and Mechanical Properties of a Plate-Shell Structure Bridge

PDF HTML XML Export Cite reminder Structural Design and Mechanical Properties of a Plate-Shell Structure Bridge DOI: 10.59238/j.pt.2023.01.006 Author: Affiliation: (1.Department of Bridge Engineering, Tongji University, Shanghai 200092, China;2.Tongji Architectural Design (Group) Co., Ltd., Shanghai 200092, China) Clc Number: Fund Project: Article | Figures | Metrics | Reference | Related | Cited by | Materials | Comments Abstract:The main bridge of Quzhou Academy Bridge is a V-shaped rigid frame bridge with a hanging hole, the span arrangement is 75 m+150 m+75 m=300 m, the middle span hanging hole was provided with a 60 m steel box girder, and the V-leg structure and the main beam are all prestressed concrete box girders with variable height. Due to the need for bridge landscapes and pedestrian viewing platforms, the large extension arc V-leg structure extends 6 m to each side of the bridge deck, and the total width is 41 m. It was necessary to consider the stress effect of the shell in the longitudinal and transverse directions. The stress and deformation of the shell in two directions are analyzed by using the finite element method solid model, and the difference between the solid model and the frame model is compared in detail. Finally, the overall structure was analyzed and checked in the modified simplified frame finite element model. Reference Related Cited by

Study on the movements and bending stresses of hangers and control measures in self-anchored rail suspension bridges

As a critical component of suspension bridges, hangers face an increasingly prominent risk of deterioration and even breakage due to relative movement and fatigue stress, posing a serious threat to bridge safety. This study investigated longitudinal movements and bending stresses of short hangers in a typical self-anchored rail suspension bridge using transient dynamic analysis. We proposed an effective method to calculate the bending stresses of hangers based on a frame finite element model (FFEM). The effects of hanger breakage on the dynamic response of bridges were further analyzed. Results showed significant relative longitudinal movements between cables and girders, causing consequential periodic bending stresses on hangers. Furthermore, the bending stresses considerably increased as the lengths of these hangers decreased. The relative longitudinal movements and bending stresses of short hangers exhibited static characteristics in self-anchored suspension bridges. The breakage of hangers induced a significant dynamic response on adjacent hangers, which bore the most redistributed loads and became critical components. Based on the static deformation characteristics of self-anchored suspension bridges, two promising measures—adding central clamps or negative stay cables—were proposed to reduce the bending stresses and improve the fatigue performance of hangers. The improvements of the two measures were comprehensively analyzed and compared. The findings of this study are significant for improving the design of rail self-anchored suspension bridges in terms of hanger safety.

Research on the Updating Method of Vehicle Frame Finite Element Model

First, the strain gauges were pasted on the front and back tie rods of the vehicle for the sake of calibration. Under the designated working conditions, the strain data of the tie rods were collected via a data acquisition unit (DEWESoft). Meanwhile, the pressure of suspension cylinder was measured, the force distribution ratio of front axle and back axle was respectively calculated through the strain data and cylinder pressure data, and the calculation formula of the distribution ratio was obtained. The calculation results were verified through a traction test of the complete vehicle. In the end, the finite element model was updated according to the test data, followed by the analysis of the structural stiffness and strength. The method proposed in this paper will considerably contribute to the improvement of finite element analysis accuracy of the complete vehicle, and moreover, it can be promoted in the design of other similar structures, with a certain reference significance.

Research on Bench Fatigue test method of frame under torsion condition

In order to predict the fatigue life of frame, a new bench test method of the frame torsion fatigue is proposed, which can approximately reflect the results of enhanced road test. The frame finite element model was established and the simulation was carried out to determine the dangerous position of fatigue life failure. The load spectrum of the fatigue dangerous position was collected, and the fatigue damage value was analyzed by the rain-flow counting method and Miner criterion. The equivalent conversion relationship of the fatigue life between bench test and road test was established. The mean error between theoretical calculation result and bench test result is 5.2 %; The mean error between theoretical calculation result and road test result is 3.85 %. The results showed that the bench test method of frame torsion fatigue can improve the precision and reliability of the frame fatigue life prediction.

Automation of wheeled vehicles load bearing frames finite-element models loading procedure by using inertia relief method and vehicle multi-body dynamics model

The paper presents a technique for strain-stress calculation using finite element analysis for wheeled vehicle’s load bearing frames with the use of loads, obtained from full vehicle multi body dynamics models (MBD models). In this technique, boundary conditions need not to be defined, as the inertia relief method used. Frame and suspension parts are imposed in MBD model as flexible bodies to increase accuracy of loads calculations. The presented method is capable to automatize loading procedure of finite-element models, thus decreasing computational costs and results processing costs while analyzing numerous load cases. As an example, strength analysis of 6x6 articulated vehicle frame is presented. Proposed method compared to “classic” finite-element frame modelling technique, which use conventional loads formulation and fixed boundary conditions. In load case “standing on ground”, calculation results with the use of two methods demonstrate high convergence in zones, located far from suspension and frame mounting joints. For load case “hanging of second axis” results are significantly different, due to ability of MBD-model to capture behavior of suspension links, and calculate true vehicle frame movement in space in particular load case. Loading procedure of frame finite element model is automated, using script, which transfer loads from MDB-model.

Development of frame finite element model for truss structures with semi-rigid connections

Development of frame finite element model for truss structures with semi-rigid connections

Strength analysis and lightweight research of a fertilizing and soil covering vehicle

In this paper, parametric modeling is carried out for the frame part of a kind of fertilizing and soil covering vehicle to define boundary conditions such as load, constraint, etc. when the frame is under the working condition of normal full load. ANSYS software is used to produce finite element model of frame, and to analyze and solve the model, so as to obtain stress and stain variation diagram of each part of frame under working condition of normal full load. The calculation result shows that: the structure of frame is able to meet the strength requirement, and the maximum value of stress is located at joint between frame and external hinge, which should be appropriately improved in thickening way. According to the result of finite element, the scheme with size optimization is employed to design the frame in lightweight way. The research result of this paper provides the theoretical basis for the design of frame of fertilizing and soil covering vehicle, which has deep theoretical significance and application value.

Design and strength analysis of a fertilizing and soil covering vehicle

In this paper, a kind of fertilizing and soil covering vehicle is designed with compact structure, easy control and substituting manual work to conduct the operations including fertilizing and soil covering. In accordance with movement, structure and loading feature of fertilizing and soil covering vehicle, parametric modeling is carried out for the frame part of this fertilizing and soil covering vehicle to define boundary conditions such as load, constraint, etc. when the frame is under the working condition of normal full load. ANSYS software is used to produce finite element model of frame, and to analyze and solve the model, so as to obtain stress and stain variation diagram of each part of frame under working condition of normal full load. The calculation result shows that: the structure of frame is able to meet the strength requirement, and the maximum value of stress is located at joint between frame and external hinge, which should be appropriately improved in thickening way. In addition, a larger deformation occurring at damper on lower part of hopper may be reduced by adding rib plate at damper on lower part of hopper. The research result of this paper provides the theoretical basis for the design of frame of fertilizing and soil covering vehicle, which has deep theoretical significance and application value.

Coupled finite element-finite difference formulation for long-term analysis of timber–concrete composite structures

This paper focuses on development of a simple frame finite element model for nonlinear analysis of timber–concrete composite (TCC) beams under long-term loads. The element formulation within the context of the force interpolation and modified fibre element is derived in which the partial interaction between the layers can be captured by discrete nonlinear springs at ends of the element. Further, a finite difference scheme is also developed to analyse variation of diffusion within the timber section with respect to relative humidity changes. Different long-term effects of timber, concrete and connection are taken into account and their formulations within the total secant approach and efficient step-by-step analysis are derived. The implementation of the proposed model in a 1D FE model is discussed and the long-term behaviour of TCC components and beams is verified with available test results from literature.

Structural health rating (SHR)-oriented 3D multi-scale finite element modeling and analysis of Stonecutters Bridge

The Stonecutters Bridge (SCB) in Hong Kong is the third-longest cable-stayed bridge in the world with a main span stretching 1,018 m between two 298 m high single-leg tapering composite towers. A Wind and Structural Health Monitoring System (WASHMS) is being implemented on SCB by the Highways Department of The Hong Kong SAR Government, and the SCB-WASHMS is composed of more than 1,300 sensors in 15 types. In order to establish a linkage between structural health monitoring and maintenance management, a Structural Health Rating System (SHRS) with relevant rating tools and indices is devised. On the basis of a 3D space frame finite element model (FEM) of SCB and model updating, this paper presents the development of an SHR-oriented 3D multi-scale FEM for the purpose of load-resistance analysis and damage evaluation in structural element level, including modeling, refinement and validation of the multi-scale FEM. The refined 3D structural segments at deck and towers are established in critical segment positions corresponding to maximum cable forces. The components in the critical segment region are modeled as a full 3D FEM and fitted into the 3D space frame FEM. The boundary conditions between beam and shell elements are performed conforming to equivalent stiffness, effective mass and compatibility of deformation. The 3D multi-scale FEM is verified by the in-situ measured dynamic characteristics and static response. A good agreement between the FEM and measurement results indicates that the 3D multi-scale FEM is precise and efficient for WASHMS and SHRS of SCB. In addition, stress distribution and concentration of the critical segments in the 3D multi-scale FEM under temperature loads, static wind loads and equivalent seismic loads are investigated. Stress concentration elements under equivalent seismic loads exist in the anchor zone in steel/concrete beam and the anchor plate edge in steel anchor box of the towers.

Finite Element Analysis of one New Type Hybrid Bus Frame

The hybrid bus frame is a vehicle’s main bearing component, in which bearing stress state is very complex. In this article, the virtual prototype vehicle model is established to extract dynamic loads between each key connecting parts and the hybrid bus frame. At the same time, the hybrid bus frame finite element model is established to make strength and stiffness analysis with dynamic loads as boundary conditions. The results verify that the strength and stiffness can meet the hybrid bus frame requirement, and the largest deformation and stress area is found. The results also can provide an important basis for correcting the frame structure. What’s more, this paper makes a comparison between the method of the frame finite element analysis based on dynamic loads and the method of the frame finite element analysis based on the statics, concluded a result that the frame finite element analysis based on dynamic loads can more accurately describe the real stress state of the frame and the analysis result is more reliable.

The Finite Element Analysis of a Heavy Semi-Trailer Frame Based on ANSYS

Frame has important effects on the performance of the whole of heavy semi-trailer. A heavy semi-trailer frame is analyzed and researched on in the finite-element way in this article. The frame of 3D geometric model is established by using Pro/E. And it was imported into the Hypermesh to establish frame finite element model. Frame are calculated by using ANSYS solver in bending condition, emergency braking conditions and rapid turn conditions of stress and deformation conditions. The computational tools and methods we used provide the new type of frame and development with a reference method to refer to in this paper.

A Truck Frame Fatigue Life Forecast Based on Virtual Prototype Technology

Frame is the stress of the main components of automobile chassis, under various direction and the form of load, the main damage form is fatigue failure under cyclic loading. In order to predict the fatigue life of the frame structure, combines the finite element analysis and multibody dynamics simulation, the vehicle multi-body dynamics model was established, and according to the China traffic simulation, the corresponding load spectrum was got. Frame finite element model was established and a strength analysis was carried out for the model, on this basis, according to the frame material fatigue performance data and load process, the fatigue life of the frame was studied by using finite element analysis software analysis, the fatigue life distribution and the position of the prone to fatigue failure of the frame were found, the results show that the strength and fatigue life of the frame were comply with the design requirements.

하중기반 유한요소모델에 의한 FRP 보강 철근콘크리트 기둥의 비선형 해석

The aim of the current study is to develop a nonlinear isoparametric layered frame finite element (FE) analysis of FRP strengthened reinforced concrete (RC) beam or column members by a force-based FE formulation. In sections, concrete is modeled in the triaxial stress-strain relationship state and the FRP sheet is modeled as layered composite materials in two-dimension. The element stiffness matrix derived by the force-based FE has the force-interpolation functions without assuming the displacement shape functions. A lateral load test of RC column strengthened by GFRP sheets was analyzed by the developed force-based FE model. From comparative studies of the experimental and analysis results, it was shown to compare with the stiffness FE method that the force-based FE analysis could give more accurate predictions in the overall lateral load-deflection response as well as in nonlinear deformations and damages in the column plastic hinge region.

Finite Element Modeling and Analysis for a Certain Urban Bus Frame

Using CATIA set up a 3d model of urban bus frame in this paper, And ANSYS13.0 is used to establish the body frame finite element model of the certain urban bus body frame, Based on this model, the static characteristics under various conditions were analyzed, and the features of stress and strain distribution are gotten. Through the analysis of calculation results, we can conclude that this body frame around the column to the rear windscreen beam junction strength in insufficient, need to increase cross-sectional area of the left column; The floor behind driver seats strength is not enough, need to add two beams to strengthen the support. And the calculation result shows that the rest of the frame has a certain extent optimization space, and can provide the basis for the next step of lightweight.

Model Reduction and Seismic Active Control of an Multi-Spanned Highway Bridge

The Eigen mode reduction method and active control and passive base isolation strategies are exerted on one continuous isolated prestressed concrete bridge. The goal of this study is to check the applicability of the eigen mode reduction method and LQR control law on the isolated continuous or rigid-connection type bridge, to find a more effective control strategy when nonlinearity is introduced. A spaced frame finite-element model is developed by a MATLAB program coded by the author, its validity is checked through comparisons with a sap2000 model. In this program, the nonlinearities of 3 different columns and 5 isolators are considered with their bilinear force-deformation relationship. the factors such as the control devices, sensors, and the corresponding noises and time delay are all considered in the model. Eigen mode reduction method was applied to set up the controllers. The seismic response measurements and regulated outputs are adjusted to optimize control effects.

Seismic Active Nonlinear Control of an Isolated Highway Bridge

Active control and passive base isolation strategies are exerted on one continuous isolated prestressed concrete bridge. The goal of this study is to check the applicability of the LQR control law on the isolated continuous or rigid-connection type bridge, to find a more effective control strategy when nonlinearity is introduced. A spaced frame finite-element model is developed by a MATLAB program coded by the author, its validity is checked through comparisons with a sap2000 model. In this program, the nonlinearities of 3 different columns and 5 isolators are considered with their bilinear force-deformation relationship. the factors such as the control devices, sensors, and the corresponding noises and time delay are all considered in the model. Model reduction technique was applied to set up the controllers. The seismic response measurements and regulated outputs are adjusted to optimize control effects.

Effect of Track Measuring Beam on the Bogie Frame Strength and Vibration Mode of Inspection Car

Track measuring beam is the most important structure in the inspection car and the vibration characteristics of it affect the inspection results and the fatigue strength of the bogie frame. In this study, the bogie frame finite element model of a inspection car were constructed and the free mode, static strength, fatigue strength and harmonic response were analyzed. The influence of the track measuring beam installation on the local modes, static strength and fatigue strength of the bogie frame were investigated and the suggestion on the method to reduce the track measuring beam vibration and improve the inspection quality was proposed.