Improving the Fatigue Resistance Of Cold Forging Tools by Fe Simulation and Computer Aided Die Shape Optimization

1992 ◽  
Vol 206 (2) ◽  
pp. 143-150 ◽  
Author(s):  
M Geiger ◽  
M Hänsel ◽  
T Rebhan
Keyword(s):  
Finite Element ◽  
Fatigue Resistance ◽  
Process Simulation ◽  
Material Flow ◽  
Cold Forging ◽  
Material Research ◽  
Fe Model ◽  
Tool Failure ◽  
Friction Forces ◽  
Computer Aided

It is the intention of the present article to point out a new method for computer aided tool optimization as part of computer integrated tool manufacturing. Based on the results of finite element (FE) analysis and subsequent tool failure simulation, it is possible to optimize the FE model of a tool already at the stage of construction, in order to enhance the service life and process reliability. The permissible degree of freedom for any shape correction, of course, is mainly limited by constructive constraints of the tool and the properties of the material flow during the extrusion process. Thus the resulting optimized geometry has to he considered as a possible constructive alternative. However, analytical as well as practical solutions already show that a parabolical or elliptical curved surface contour, replacing a regular radius, not only improves the fatigue resistance but may have a positive influence on material flow behaviour, friction forces and resulting tool loads as well (1). The influence imposed on the material flow by the geometrical modification of the die shape will be clarified in future by the results of FE process simulation. A renewed simulation run, employing the optimized shape, may be conducted immediately after the optimization process. Along with current material research, the simulation of tool failure based on the finite element method (FEM) analysis of forging techniques (FE process simulation) therefore represents a promising direction for future developments (2–4).

BIOMECHANICAL ANALYSIS OF INTERBODY AND POSTEROLATERAL FUSION WITH TRANSPEDICULAR SCREW FIXATION FOR SPONDYLOLISTHESIS: A FINITE ELEMENT STUDY

2008 ◽  
Vol 20 (03) ◽  
pp. 145-151 ◽  
Author(s):  
Heng-Liang Liu ◽  
Ming-Tsung Sun ◽  
Chun-Li Lin ◽  
Hsin-Yi Cheng ◽  
Kou-Chen Wei ◽  
...  
Keyword(s):  
Finite Element ◽  
Interbody Fusion ◽  
Screw Fixation ◽  
Posterolateral Fusion ◽  
Fe Model ◽  
Functional Spinal Unit ◽  
Transpedicular Screw ◽  
Flexion Extension ◽  
Computer Aided ◽  
Transpedicular Screw Fixation

This study investigates and compares the mechanical response of interbody and posterolateral fusion along with the transpedicular screw fixation for the degenerative spondylolisthesis under different load conditions using finite element (FE) analysis. Image processing, computer aided design (CAD), and computer aided engineering techniques were applied to build a three-dimensional model of a functional spinal unit (L4–L5) with transpedicular screw fixation for the posterolateral fusion FE model. Additionally, the intervertebral disc was replaced by two cages to represent the interbody fusion FE model. A unit moment of 1 Nm was applied on the top of L4 in different directions to simulate the flexion, extension, lateral bending, and axial rotation, respectively. The lower of L5 was fixed in all directions for constraint. The simulated results revealed that using cages obviously decreased (13%–58%) the stress imposed upon the instrumentations. The stress concentration occurred at the locking nut on the transpedicular screw head, the middle part of the bone plate, and the thread of transpedicular screw near the head. These findings were comparable to clinical observations. With the limited data, our results suggested interbody fusion in combination with transpedicular screw fixation demonstrated less stress on the instrumentations than the posterolateral fusion with only transpedicular screw fixation.

3D Finite Element Modeling of an Assembly Process With Thread Forming Screw

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Florestan Mathurin ◽  
Jean Guillot ◽  
Pierre Stéphan ◽  
Alain Daidié
Keyword(s):  
Finite Element ◽  
Material Flow ◽  
Hole Diameter ◽  
Fe Model ◽  
Assembly Process ◽  
Forming Process ◽  
3D Finite Element ◽  
Accurate Representation ◽  
Simulation Results ◽  
Principal Elements

This paper presents a 3D finite element (FE) model of a thread forming screw assembly process based on the ABAQUS 6.5.4 Explicit software program. The model consists of two principal elements: an M10×12 thread forming screw and a lower 4 mm plate into which the screw taps its threads. The aim was to develop a robust industrial dimensioning tool; the model can be extended to establish the preload and investigate other types of assemblies. A 45 deg sector, which represents 1/8 of the joint, was modeled to maintain a good compromise between calculation time and an accurate representation of the thread forming process. The intent of the study was to analyze the material flow throughout the thread forming process; a parametrical study was also conducted to identify the most influential process parameters. To validate the model, FE numerical simulation results are compared with published experimental results. The study shows that the lead hole diameter has an important influence on the screwing torque.

scholarly journals Effect of floating axial holder on oscillating cold forging of spline shaft

2018 ◽  
Vol 249 ◽  
pp. 02001
Author(s):  
N Y Ben ◽  
Q Zhang ◽  
M G Lee
Keyword(s):  
Material Flow ◽  
Elastic Recovery ◽  
Nonlinear Function ◽  
Material Model ◽  
Cold Forging ◽  
Fe Model ◽  
Tooth Shape ◽  
Constitutive Material Model ◽  
Spline Shaft ◽  
Forming Defects

Oscillating technique is applied into the axial forging process of spline shaft to decrease the forming load and improve the quality of products. A floating axial holder with dwell force is designed to control the material flow. The influences of the floating axial holder have been analysed by finite element (FE) simulation and then verified by experiments. A FE model that considers material property change, elastic recovery and elastoplastic friction was built. The constitutive material model, which is mainly composed of variable elastic modulus and rate-dependent hardening, was used to simulate changes in material properties. Results showed that material flow was improved by decreasing dwell force. Tooth shape can be controlled by changing the dwell force of floating axial holder. The nonlinear function between addendum circle diameter and dwell force has been found. Hence, an optimal value of dwell force was determined considering the forming force, forming defects and tooth shape. Based on the simulating results, the optimal and irrational parameters of dwell force and frequency have been compared in the experiments. The typical defects of flash and accumulation can be eliminated by using the floating axial holder with optimal parameters.

An Investigation on Elastic-Plastic Rolling Contact Over Rough Surfaces Using a 3-D Dynamic Finite Element Model

2008 ◽  
Author(s):  
Xin Zhao ◽  
Zili Li ◽  
Rolf Dollevoet
Keyword(s):  
Finite Element ◽  
Rough Surface ◽  
Rough Surfaces ◽  
Maximum Shear Stress ◽  
Rolling Contact ◽  
Fe Model ◽  
Stress Distributions ◽  
Friction Forces ◽  
Elastic Plastic ◽  
Dynamic Finite Element

A full-scale 3-D dynamic finite element (FE) model is created to solve the elastic-plastic wheel-rail rolling contact over rough surfaces under different friction forces. Both normal and tangential loads are applied properly. A bi-linear plastic material model is introduced and the real wheel and rail head geometries are simulated. The rolling of a drive wheel with full friction exploitation over a rough contact surface is analyzed in this paper. The stress distributions at the zone with rough surface are derived. From the results at a selected instant, it is found that roughness significantly increases the stress level of the surface layer. Furthermore, plasticity can greatly reduce stress peaks and change stress distributions. The maximum shear stress distribution at the rough surface is also analyzed to assess effects of roughness on fatigue crack initiation.

Finite Element Modeling and Analysis of Friction Wedge Damping During Suspension Bounce Modes

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Y. Q. Sun ◽  
C. Cole
Keyword(s):  
Finite Element ◽  
Static Problem ◽  
Element Model ◽  
Fe Model ◽  
Friction Damping ◽  
Damping Force ◽  
Friction Forces ◽  
Modeling And Analysis ◽  
Damping Characteristics ◽  
Dimensional Finite Element

A two-dimensional finite element model (2D FEM) has been developed to improve the modeling and understanding of the friction damping characteristics of freight bogie suspensions. The specific suspension considered utilizes friction dampers with constant preload force as are widely used in three-piece bogie wagons in Australia. Unlike simpler models commonly used in rail vehicle dynamics, the FE model developed can accommodate distributed normal forces across the wedge surfaces. The model was tested in bounce modes and compared with the normal equations used to model wedge friction forces, which treat the forces on the wedge as a static problem. The simulation results using the 2D FEM model showed that the friction damping force is not constant and changes when the suspension is in motion. It was also shown that the force changes magnitude during the loading and unloading situations. The factors, which affect the change in friction force, are the friction characteristics on wedge contact surfaces, the direction and change in tangent force on wedge angular surface, the elastic deformation of the wedge, the wedge relative movement, and the wedge structure arrangement. The FE model assumptions are investigated and insights on wedge friction and creepage discussed.

Cold Forging Die Design and Process Simulation of a Disk with Inner Ring Gear

2014 ◽  
Vol 626 ◽  
pp. 211-216
Author(s):  
Cheng Hsien Yu ◽  
Jinn Jong Sheu
Keyword(s):  
Process Simulation ◽  
Material Flow ◽  
Die Design ◽  
Cold Forging ◽  
Volume Distribution ◽  
Ring Gear ◽  
Multi Stage ◽  
Forging Die ◽  
And Control ◽  
Flow Interference

Cold forging die design and process simulation were studied in this paper for a disk with center boss and outer ring gear. The complexity of part geometry results in defects of under-filling and folding. The material flow interference in the radial and the axial directions at the corner areas is the main reason of the occurrence of defects. A multi-stage cold forging process was proposed to control the material flow and volume distribution simultaneously. FEM simulations were carried out to evaluate the designs of process and die. The proposed preform and web geometry designs were able to decrease the forging load and control the material flow. The simulation results showed the proposed methods were able to make this forged part without defects.

Development of APDL Program for Analysis of Composite Material Multicell Beams

2012 ◽  
Vol 510-511 ◽  
pp. 609-616
Author(s):  
Muhammad Mushtaq Tariq ◽  
Mustafa Pasha ◽  
Malik Nazir Ahmed ◽  
Azhar Munir
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Finite Elements ◽  
Complex Geometry ◽  
Industrial Applications ◽  
Parametric Modeling ◽  
Material Research ◽  
Fe Model ◽  
Error Criterion ◽  
Element Analysis

Comparison of finite elements and comparison of ANSYS with MSC Patran Nastran, for analysis of composite material multicell beams, is the main idea of this paper. The Finite Element Analysis (FEA) is a valuable tool of modeling and simulation in development, processing, production and application of modern hi-tech materials and structures for reliable design. Multicell beams have important industrial applications in the automotive and aerospace sectors. ANSYS Parametric Design Language (APDL) is an important language in parametric modeling and analysis of structures with simple to complex geometry. Its major advantage is virtual prototyping which can be used to analyze and compare different materials. This work introduces core techniques required for APDL using the case study of composite multicell beams subjected to constrained torsional loading. The published results using MSC NASTRAN have been verified using ANSYS and the corresponding arising issues and notes are the focus of this research study. The details of geometry, material and boundary conditions have been explained in order to construct Finite Element (FE) model. This FE model was simulated several times in ANSYS by the authors using various options of APDL language. A step-wise flowchart was used to detect and reduce problems in iterations of analysis in APDL programming. Results of FEA largely depend on FE model and software used. These issues become prominent while trying to verify results of MSC NASTRAN with ANSYS. The author has introduced three error criteria to select an equivalent finite element of one FEA package (ANSYS) for an equivalent element of other FEA package (MSC NASTRAN). These criteria are the relative error criterion, the absolute error criterion and the combined error criterion. The results from this research provide an insight into finite elements for reliability in design of composite materials. The practical milestones for research to develop FE model and APDL programs related to material research field are also manifested through this paper.

Representation of bolted joints in a structure using finite element modelling and model updating

2020 ◽  
Vol 14 (3) ◽  
pp. 7141-7151 ◽  
Author(s):  
R. Omar ◽  
M. N. Abdul Rani ◽  
M. A. Yunus
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Model Updating ◽  
Complex Structure ◽  
Bolted Joints ◽  
Model Parameters ◽  
Fe Model ◽  
Bolted Joint ◽  
Fe Modelling ◽  
Joint Structure

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

Metal Forming and the Finite-Element Method

1989 ◽  
Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Metal Forming ◽  
Computer Aided Design ◽  
The Finite Element Method ◽  
Forming Technology ◽  
Computer Aided ◽  
Deformation Mechanics ◽  
Aided Design ◽  
Element Method

The application of computer-aided design and manufacturing techniques is becoming essential in modern metal-forming technology. Thus process modeling for the determination of deformation mechanics has been a major concern in research . In light of these developments, the finite element method--a technique by which an object is decomposed into pieces and treated as isolated, interacting sections--has steadily assumed increased importance. This volume addresses advances in modern metal-forming technology, computer-aided design and engineering, and the finite element method.

scholarly journals Influence of finite element mesh size on the carrying capacity analysis of single-row ball slewing bearing

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Peiyu He ◽  
Qinrong Qian ◽  
Yun Wang ◽  
Hong Liu ◽  
Erkuo Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Mesh Size ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Mesh ◽  
Heavy Load ◽  
Slewing Bearing ◽  
Maximum Contact ◽  
Slewing Bearings

Slewing bearings are widely used in industry to provide rotary support and carry heavy load. The load-carrying capacity is one of the most important features of a slewing bearing, and needs to be calculated cautiously. This paper investigates the effect of mesh size on the finite element (FE) analysis of the carrying capacity of slewing bearings. A local finite element contact model of the slewing bearing is firstly established, and verified using Hertz contact theory. The optimal mesh size of finite element model under specified loads is determined by analyzing the maximum contact stress and the contact area. The overall FE model of the slewing bearing is established and strain tests were performed to verify the FE results. The effect of mesh size on the carrying capacity of the slewing bearing is investigated by analyzing the maximum contact load, deformation, and load distribution. This study of finite element mesh size verification provides an important guidance for the accuracy and efficiency of carrying capacity of slewing bearings.

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