Stress Analysis and Improvement of Extrusion Dies Using Combination of FEM with Taguchi Method

2015 ◽  
Vol 764-765 ◽  
pp. 143-147
Author(s):  
Kao Hua Chang ◽  
Ching Wei Shih ◽  
Gow Yi Tzou
Keyword(s):  
Taguchi Method ◽  
Principal Stress ◽  
Fem Simulation ◽  
Cobalt Content ◽  
Maximum Principal Stress ◽  
Simulation Software ◽  
Extrusion Dies ◽  
Assembly Method ◽  
Die Materials ◽  
Reference Parameters

This study aims at analyzing the influence of the maximum principal stress on Tungsten Carbide Steel die core in an extrusion die which caused the crack of die core, and then adjusts the dies assembly method in order to improve the service life of die. In this study, combining FEM simulation software with Taguchi Method L9(34) is to choose the cobalt content for die core materials, and the quantity of shrink fit while assembling the die core and die case as the reference parameters. When carrying out the simulation process, compared the changes of the maximum principal stress of the die core caused by the plastic deformation of die materials to achieve the minimum expected value as the goal be chosen the most optimal die combination. Then, the results obtained are to make dies in trial and mass-production practically; as a result, it can be achieved that the die life is improved from the original 1000pcs to 150000pcs, which is more 150 times better than before.

DEFECT IMPROVEMENT OF EXTRUSION DIES USING COMBINATION OF FEM STRESS ANALYSIS WITH THE TAGUCHI METHOD

2015 ◽  
Vol 39 (3) ◽  
pp. 729-738 ◽  
Author(s):  
Kao-Hua Chang ◽  
Ching-Wei Shih ◽  
Gow-Yi Tzou
Keyword(s):  
Taguchi Method ◽  
Principal Stress ◽  
Fem Simulation ◽  
Cobalt Content ◽  
Maximum Principal Stress ◽  
Simulation Software ◽  
Extrusion Dies ◽  
Assembly Method ◽  
Die Materials ◽  
Reference Parameters

This study aims at analyzing the influence of the maximum principal stress on Tungsten Carbide Steel die core in an extrusion die which caused the crack of die core, and then adjusts the dies assembly method in order to improve the service life of die. In this study, we combine FEM simulation software with the Taguchi Method L9(34) to choose the cobalt content for die core materials, and the quantity of shrink fit while assembling the die core and die case as the reference parameters. When carrying out the simulation process, we compared the changes of the maximum principal stress of the die core caused by the plastic deformation of die materials to achieve the minimum expected value as the goal for the most optimal die combination. Then, the results obtained are to make dies in trial and mass-production practically; as a result, the die life is improved from the original 1000 to 150,000 pcs, which is more than 150 times better than before.

scholarly journals Forming parameters optimizations with drawing force and die stress in wire rod drawing using rotating die under Coulomb friction

2018 ◽  
Vol 185 ◽  
pp. 00025
Author(s):  
Ing-Kiat Tiong ◽  
Un-Chin Chai ◽  
Gow-Yi Tzou
Keyword(s):  
Taguchi Method ◽  
Coulomb Friction ◽  
Effective Strain ◽  
Fem Simulation ◽  
Frictional Coefficient ◽  
Simulation Software ◽  
Drawing Force ◽  
Wire Rod ◽  
Forming Parameters ◽  
Die Stress

An optimization research is performed on the related forming parameters of wire rod drawing through a rotating die under Coulomb friction. The optimization research is conducted through finite element method (FEM) simulation combined with Taguchi method. There are two drawing characteristic optimizations have been carried out. They are the optimizations with drawing force and die stress. The forming parameters considered in this study are half die angle, frictional coefficient, die fillet, and rotating angular velocity of the rotating die. The same procedure is carried out in both optimizations. The geometrical models of the wire rod, top die and rotating die are constructed firstly in SolidWorks and imported into the FEM simulation software named DEFORM 3D. With the aid of Taguchi method, the simulation experiments are carried out. The results such as drawing force, die stress, and the corresponding signal-to-noise (S/N) ratio are obtained and compared. The influence rank of the forming parameters and the optimal combination of parameters are obtained through the response table for both optimizations. The results such as effective stress, effective strain, velocity field, drawing force, and die stress are studied. The results show that the minimizations of drawing force and die stress are successfully achieved.

Drawing Force Optimization Research on Forming Parameters of Drawing Wire Rod with Rotating Die under Coulomb Friction

2018 ◽  
Vol 920 ◽  
pp. 3-9
Author(s):  
Un Chin Chai ◽  
Gow Yi Tzou ◽  
Ing Kiat Tiong
Keyword(s):  
Taguchi Method ◽  
Coulomb Friction ◽  
Effective Strain ◽  
Fem Simulation ◽  
Simulation Software ◽  
Optimal Parameters ◽  
Drawing Force ◽  
Force Optimization ◽  
Forming Parameters ◽  
Deform 3D

An optimization research based on the drawing force is done on several forming parameters of metal rod drawing through a rotating die under Coulomb friction. The metal rod and the rotating die are constructed in SolidWorks and imported into FEM simulation software named DEFORM 3D. In this study, the FEM simulation is carried out by using DEFORM 3D combining with Taguchi method to explore the effective stress, the effective strain, and the velocity field. The influence rank of parameters to the drawing force is obtained, and the optimal parameters’ combination is determined by using Taguchi method. Results show that the optimization of drawing force is achieved and the minimum drawing force is successfully obtained.

scholarly journals Failure Characteristics and Stability Control of Roadway Surrounding Rocks under Different Lateral Pressure Coefficients

2020 ◽  
Vol 13 (5) ◽  
pp. 42-49
Author(s):  
Zhiyu Chen ◽  
◽  
Zhiqiang Yin ◽  
Jucai Chang ◽  
Wenbao Shi ◽  
...  
Keyword(s):  
Principal Stress ◽  
Lateral Pressure ◽  
Pressure Coefficient ◽  
Maximum Principal Stress ◽  
Stability Control ◽  
Simulation Software ◽  
Particle Flow Code ◽  
Lateral Pressure Coefficient ◽  
Working Face ◽  
The Stability

The stability control of mining roadways is crucial in ensuring the safe and efficient mining of deep coal resources. Given the effect of mining stress on the working face, the support scheme of such roadways, which is designed based on the original in-situ stress parameters, often presents support-related problems. A mining roadway on the 1131 working face of Zhujidong Coal Mine in the Huainan mining area, China was taken as the engineering background of this study. To explore the influence of mining stress on the stability control of this roadway, the 2-dimensional (2D) Particle Flow Code (PFC) numerical simulation software was used to perform a simulation study on the stress distribution characteristics and deformation failure laws of the surrounding rocks under the change in the roadway lateral pressure coefficient caused by the mining stress. An improved support scheme that considers the influence of varying lateral pressure coefficient on the mining roadway was then proposed. Results show that when the lateral pressure coefficient increased from 1 to 1.4, the maximum principal stress (61.2 MPa) is observed at 2.9 m inside the roof of the surrounding rocks in the roadway. When the lateral pressure coefficient decreases from 1 to 0.4, the maximum principal stress (46.2 MPa) is observed at 2.2 m inside the surrounding rock of sidewalls of the roadway, and failure occurs. These findings suggest that the deformation and failure of surrounding rocks are affected regardless of the lateral pressure coefficient increase or decrease. On this basis, the lengths of the anchor bolts in the roof and sidewalls in the original support method are increased from 2,200 mm to 3,000 mm and 2,500 mm, respectively. The field monitoring results indicate that the improved support method mitigates the deformation and realizes the stability control of the roadway surrounding rocks. The findings of this study could provide a scientific basis for the parameter design of roadway support.

scholarly journals Elastic Simulation of Joints with Particle-Based Fluid

2021 ◽  
Vol 11 (15) ◽  
pp. 6900
Author(s):  
Su-Kyung Sung ◽  
Sang-Won Han ◽  
Byeong-Seok Shin
Keyword(s):  
Principal Stress ◽  
Human Body ◽  
Yield Condition ◽  
Maximum Principal Stress ◽  
Human Motion ◽  
The Difference ◽  
The Moment ◽  
External Forces ◽  
Physical Changes ◽  
Elastic Simulation

Skinning, which is used in skeletal simulations to express the human body, has been weighted between bones to enable muscle-like motions. Weighting is not a form of calculating the pressure and density of muscle fibers in the human body. Therefore, it is not possible to express physical changes when external forces are applied. To express a similar behavior, an animator arbitrarily customizes the weight values. In this study, we apply the kernel and pressure-dependent density variations used in particle-based fluid simulations to skinning simulations. As a result, surface tension and elasticity between particles are applied to muscles, indicating realistic human motion. We also propose a tension yield condition that reflects Tresca’s yield condition, which can be easily approximated using the difference between the maximum and minimum values of the principal stress to simulate the tension limit of the muscle fiber. The density received by particles in the kernel is assumed to be the principal stress. The difference is calculated by approximating the moment of greatest force to the maximum principal stress and the moment of least force to the minimum principal stress. When the density of a particle increases beyond the yield condition, the object is no longer subjected to force. As a result, one can express realistic muscles.

FEM Stress Analysis and Strength of Scarf Adhesive Joints of Similar Adherend Subjected to Impact Tensile Loadings

2007 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Yuya Hirayama ◽  
He Dan
Keyword(s):  
Young’S Modulus ◽  
Principal Stress ◽  
Stress Wave ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Adhesive Joints ◽  
Stress Wave Propagation ◽  
Adhesive Thickness ◽  
Three Dimensional Finite Element

The stress wave propagation and stress distribution in scarf adhesive joints have been analyzed using three-dimensional finite element method (FEM). The FEM code employed was LS-DYNA. An impact tensile loading was applied to the joint by dropping a weight. The effect of the scarf angle, Young’s modulus of the adhesive and adhesive thickness on the stress wave propagations and stress distributions at the interfaces have been examined. As the results, it was found that the point where the maximum principal stress becomes maximum changes between 52 degree and 60 degree under impact tensile loadings. The maximum value of the maximum principal stress increases as scarf angle decreases, Young’s modulus of the adhesive increases and adhesive thickness increases. In addition, Experiments to measure the strains and joint strengths were compared with the calculated results. The calculated results were in fairly good agreements with the experimental results.

Influence of Slope Gradient on Distribution Rule of Geostress Field in River Valleys

2013 ◽  
Vol 404 ◽  
pp. 365-370 ◽  
Author(s):  
Qi Tao Pei ◽  
Hai Bo Li ◽  
Ya Qun Liu ◽  
Jun Gang Jiang
Keyword(s):  
Numerical Simulation ◽  
Stress Concentration ◽  
Principal Stress ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Slope Gradient ◽  
Bank Slope ◽  
Distribution Rule ◽  
River Valleys ◽  
Gradient Change

During the construction of hydropower station, the change of slope gradient in river valleys often takes place. In order to study influence of slope gradient change on distribution rule of geostress field, the three dimensional unloading models under different slope gradients were established by finite difference software (FLAC3D). After numerical simulation, the results were as follows: (1) The phenomenon of stress concentration at the bottom of river valleys was obvious, which appeared the typical stress fold. Both the depth of stress concentration zone and the principal stress values significantly increased with the increment of slope gradient. (2) Maximum principal stress values increased less in shallow part of upper bank slope (low stress zone) but increased more in the nearby slope foot with the increment of slope gradient, causing great difference in geostress field of bank slope. (3) There was some difference in released energy of bank slope due to slope gradient change in river valleys. In order to distinguish the difference, stress relief zone was further divided into stress stably released zone and stress instability released zone. Finally, take Ada dam area of the western route project of South-to-North Water Transfer as an example, the results by numerical simulation were reliable through comparing the distribution rule of geostress field for the dam, which could provide important reference for stability of the design and construction of steep and narrow river valleys.

scholarly journals Predictions of Optimum Forming Conditions in Press Forming using TAGUCHI Method and FEM Simulation

2006 ◽  
Vol 72 (721) ◽  
pp. 3044-3051 ◽  
Author(s):  
Hiroyuki SUGAI ◽  
Ikuo TANABE ◽  
Junnosuke MIZUTANI ◽  
Shingo SUGII ◽  
Satoshi KATAYAMA
Keyword(s):  
Taguchi Method ◽  
Fem Simulation ◽  
Press Forming

scholarly journals Influence of fibromucosa height and loading on the stress distribution of a total prosthesis: a finite element analysis

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Tarcisio José de Arruda Paes Junior ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Viviane Maria Gonçalves de Figueiredo ◽  
Alexandre Luiz Souto Borges ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Principal Stress ◽  
Maximum Principal Stress ◽  
Element Analysis ◽  
Total Displacement ◽  
Anterior Guidance ◽  
Mandibular Movements

Purpose: To evaluate the effect of fibromucosa height on the stress distribution and displacement of mandibular total prostheses during posterior unilateral load, posterior bilateral load and anterior guidance using the finite element analysis (FEA). Material and methods: 3D virtual models were made to simulate the stress generated during different mandibular movements in a total prosthesis. The contacts were simulated according to the physiology, being considered perfectly bonded between cortical and medullar bones; and between cortical bone and mucosa. Non-linear frictional contact was used for the total prosthesis base and fibromucosa, allowing the prosthesis to slide over the tissue. The cortical bone base was fixed and the 100 N load was applied as unilateral load, posterior bilateral load and anterior guidance simulation. The required results were for maximum principal stress (MPa), microstrain (mm/mm) and total displacement (mm). The numerical results were converted into colorimetric maps and arranged according to corresponding scales. Results: The stress generated in all situations was directly proportional to the fibromucosa height. The maximum principal stress results demonstrated greater magnitude for anterior guidance, posterior unilateral and posterior bilateral, respectively. Only posterior unilateral load demonstrated an increase in bone microstrain, regardless of the fibromucosa height. Prosthesis displacement was lower under posterior bilateral loading. Conclusion: Posterior bilateral loading is indicated for total prosthesis because it allows lower prosthesis displacement, lower stress concentration at the base of the prosthesis and less bone microstrain.   Keywords Finite element analysis; Occlusion; Total prosthesis.

Dynamic modeling of bedding-plane slip during hydraulic fracturing

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. KS95-KS104 ◽  
Author(s):  
Zhenhua He ◽  
Benchun Duan
Keyword(s):  
Principal Stress ◽  
Slip Length ◽  
Vertical Plane ◽  
Bedding Plane ◽  
Maximum Principal Stress ◽  
Reservoir Properties ◽  
Dynamic Stresses ◽  
Initiation Point ◽  
Principal Stress Direction ◽  
Cotton Valley

Whether the tip stresses around a dynamically propagating hydraulic fracture (HF) could activate a bedding plane (BP) or not is an important question for HF propagation and microseismicity generation. BP slip has been proposed to be one main source of microseismicity during HF treatments in unconventional reservoirs. However, a BP perpendicular to a principal stress direction is unlikely to be activated in a simple geomechanical model. We have applied a dynamic finite-element geomechanics method to examine the induced dynamic shear stress and the activation of BPs that are perpendicular to the HF based on the Cotton-Valley tight-sand reservoir properties. We work in a 2D vertical-plane framework. The induced dynamic stresses around a HF tip could be significant. We explore three different scenarios for the BP activation. In the first scenario, an HF is dynamically propagating toward two symmetric BPs, but has not touched them yet. We find that only low-strength BPs can be activated in this scenario. In the second scenario, an HF dynamically propagates toward two symmetric BPs and then it crosses them by a short distance. The BPs could be more easily activated in this scenario compared with the first scenario. The slip length and maximum slip decrease with cohesion, critical slip distance, or maximum principal stress. In the third scenario, an HF dynamically propagates toward two symmetric BPs, and then fluid invasion into the BPs occurs after the HF touches them. Large shear slippage and slip length happen in this scenario because fluid invasion weakens the BPs. In all of the scenarios, different senses of shear could occur along the BPs and a rupture typically propagates bilaterally from the initiation point on the BPs.

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