Stress Analysis of Forging Dies for Inverse Extrusion

2015 ◽  
Vol 661 ◽  
pp. 44-51 ◽  
Author(s):  
Kao Hua Chang ◽  
Ching Wei Shih ◽  
Gow Yi Tzou
Keyword(s):  
Compressive Strength ◽  
Tungsten Carbide ◽  
Compressive Stress ◽  
Hoop Stress ◽  
Longitudinal Crack ◽  
Fem Simulation ◽  
Simulation Software ◽  
Forging Process ◽  
Carbide Alloy ◽  
Shrink Fit

This study intended to investigate the longitudinal crack on the tungsten carbide alloy die core that caused by the influence of receiving the hoop tensile stress in the process of inverse extrusion. Therefore, the shrink fit is adopted to design the die core and stress ring, and assemble the die case, in order to yield the hoop compressive stress in advance, which can be used to resist the tensile hoop stress yielded from the forging process. It also applied the FEM simulation software and Taguchi Method L9(34) in this study to simulate various combinations of different shrink fits, in order to obtain the best combination of die. Moreover, it focused on the compressive strength of material characteristics for the tungsten carbide alloy steel die core, and properly adjusted the shrink fit to prevent an early crack on the die core that caused by the hoop compressive stress in advance, in order to achieve the best result.

Assembly of Compound Tubes Under Hydraulic Pressure

2006 ◽  
Vol 128 (2) ◽  
pp. 208-211 ◽  
Author(s):  
Tony D. Andrews
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
Plastic Strain ◽  
Compressive Stress ◽  
Bauschinger Effect ◽  
No Reduction ◽  
Hydraulic Pressure ◽  
Maximum Compressive Stress ◽  
Compressive Stresses ◽  
Shrink Fit

This paper describes a method for inserting a tapered liner into a sleeve while the latter is expanded by hydraulic pressure. The technique avoids many of the limitations associated with traditional shrink fit techniques and autofrettage. The sleeve and liner are manufactured with internal and external tapers, respectively, to give the appropriate interference for the finished compound tube. The liner is mounted on a rod and positioned loosely inside the sleeve. The ends of the sleeve are sealed with plugs, which allow the rod to protrude through each end and which also have hydraulic oil inlets. Once the assembly has been pressurized, the rod is pushed into the vessel to move the liner further into the sleeve generating an interference once the pressure in the sleeve is removed. Insertion of a relatively thin liner can generate high residual compressive stresses at the bore, similar to autofrettage but with a shallower gradient away from the bore. Because the liner is not subjected to plastic strain during manufacture, there is no reduction in compressive strength due to the Bauschinger effect and the maximum compressive stress obtainable is greater than that from traditional autofrettage routes. Such high stresses lead to excess tension in the sleeve, which must be reduced by autofrettaging the sleeve prior to assembly of the compound tube. Such a configuration is suitable for inserting a part-length liner at the chamber for strength and/or wear resistance and tensile stresses can be eliminated to prevent failure of brittle materials, such as ceramics.

Die stress analysis and improvement of the welding valve fastener in multi-stage forging

2020 ◽  
Vol 44 (2) ◽  
pp. 263-271
Author(s):  
Gow-Yi Tzou ◽  
Shih-Hsien Lin ◽  
Dyi-Cheng Chen ◽  
Un-Chin Chai
Keyword(s):  
Stress Concentration ◽  
Hoop Stress ◽  
Axial Stress ◽  
Maximum Principal Stress ◽  
Simulation Software ◽  
Die Design ◽  
Cold Forming ◽  
Multi Stage ◽  
Die Stress ◽  
Shrink Fit

This study explores the multi-stage cold forming die of a welding valve fastener using simulation software. It is possible to understand the various stress intensities of the die core bore and the corresponding distributions during each forging stage so as to improve the service life of the die. These stresses include radial stress, axial stress, hoop stress, and maximum principal stress, as well as the different types of stresses that could cause different fractures of the die core. Therefore, it is necessary to use different die design methods to improve the fracture issues for different die cores. For example, shrink fit can be used between the die core and die case. By adjusting the size of the shrink fit, tensile hoop stress can be converted into compressive hoop stress, which can avoid the generation of axial cracking of the die during the forging formation. In addition, drastic changes in axial stress caused by the stress concentration on the die core can yield a transverse crack of the die core. Thus adopting preventative measures by split such a stress concentration into two sections reduces the drastic changes in axial stress on that section.

COLMONOY No. 83 PTA

Alloy Digest ◽  
1995 ◽  
Vol 44 (12) ◽  
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
Physical Properties ◽  
Tungsten Carbide ◽  
Tensile Properties ◽  
Powder Metal ◽  
Application Method ◽  
Plasma Transferred Arc ◽  
Transferred Arc ◽  
Nickel Base

Abstract COLMONOY No. 83 PTA is a nickel-base hard surfacing alloy containing tungsten carbide. The application method is plasma transferred arc and the application is designed to protect extrusion screws. This datasheet provides information on composition, physical properties, microstructure, hardness, tensile properties, and compressive strength. It also includes information on wear resistance as well as machining and powder metal forms. Filing Code: Ni-493. Producer or source: Wall Colmonoy Corporation.

scholarly journals Predicting the behavior of reinforced concrete columns confined by fiber reinforced polymers using data mining techniques

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Sahar Y. Ghanem ◽  
Heba Elgazzar
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Compressive Stress ◽  
Compressive Strain ◽  
Concrete Columns ◽  
Steel Reinforcement ◽  
Fiber Reinforced Polymers ◽  
Stress And Strain ◽  
Fiber Reinforced ◽  
The Impact

AbstractFiber Reinforced Polymer (FRP) usage to wrap reinforced concrete (RC) structures has become a popular technology. Most studies about RC columns wrapped with FRP in literature ignored the internal steel reinforcement. This paper aims to develop a model for the axial compressive strength and axial strain for FRP confined concrete columns with internal steel reinforcement. The impact of FRP, Transverse, and longitudinal reinforcement is studied. Two non-destructive analysis methods are explored: Artificial Neural Networks (ANNs) and Regression Analysis (RA). The database used in the analysis contains the experimental results of sixty-four concrete columns under the compressive concentric load available in the literature. The results show that both models can predict the column's compressive stress and strain reasonably with low error and high accuracy. FRP has the highest effect on the confined compressive stress and strain compared to other materials. While the longitudinal steel actively contributes to the compressive strength, and the transverse steel actively contributes to the compressive strain.

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.

Numerical Simulation Analysis on Cold Closed-Die Forging of Differential Satellite Gear in Car

2008 ◽  
Vol 575-578 ◽  
pp. 517-524 ◽  
Author(s):  
Yao Zong Zhang ◽  
Jian Bo Huang ◽  
Xue Lin ◽  
Quan Shui Fang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Bevel Gear ◽  
Cold Forging ◽  
Forging Process ◽  
Die Forging ◽  
Closed Die Forging ◽  
Forming Defects ◽  
Deform 3D

The cold closed-die forging process of the gear is a kind of new technique of the precise forming of gear in recent years. In this paper, the cold closed-die forging process of differential satellite gear in car was analyzed through numerical simulation method. Forming mold was designed with Pro/E Wildfire2.0 which included four components : upper punch, lower punch, tooth shape upper die and lower die for Normal Cone. The three-dimensional models of satellite bevel gear mould were built and imported into numerical simulation software DEFORM-3D. Because the gear has the uniform circumferential features, in order to save time and improve the accuracy, only one tooth was simulated, and the full simulation outcome of 10 teeth was mirrored from this one. Through the numerical simulation analysis of DEFORM-3D, the instantaneous deformation and stress filed were gained. Forming defects were forecasted and the cold closed-die forging rule for satellite gear used in car was obtained which can provide effective references for no-flash cold forging process of planet bevel gear and the mold design.

FEM simulation of hot forging process to predict microstructure evolution

2013 ◽  
Author(s):  
Shi-Hong Zhang ◽  
Hai-Yan Zhang ◽  
Hong-Wu Song ◽  
Ming Cheng
Keyword(s):  
Microstructure Evolution ◽  
Hot Forging ◽  
Fem Simulation ◽  
Forging Process ◽  
Hot Forging Process

Numerical Simulation and Parameter Optimization on Forming Process of Automobile Torque Box

2014 ◽  
Vol 722 ◽  
pp. 140-146
Author(s):  
Wen Juan Zhang ◽  
Long Wu ◽  
Gang Chen
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Parameter Optimization ◽  
Process Parameters ◽  
Fem Simulation ◽  
Simulation Software ◽  
Drawing Process ◽  
Forming Process ◽  
Element Simulation

In this paper the drawing process of Box-torque was simulated by Dynaform, which is FEM simulation software. The process parameters, which affected the quality of forming, were optimized by finite element simulation. The emphasis was focus on the optimization of draw-bead and BHF and data were summarized from the optimization graphs. In this simulation, lengthways draw-bead was set on the technical face for reducing or eliminating wrinkle. It was innovation difference from the usual that the draw-bead was set on binder. Finally the correctness of simulation was approved by comparing the optimization of simulation with the data of experimentation.

Compressive Stress of Syntactic Foam: Effect of rNBR Particles Reinforced Epoxy Macrospheres (rNBR-EM)

2018 ◽  
Vol 280 ◽  
pp. 301-307
Author(s):  
Z. Zakaria ◽  
C.Y. Yao
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Compressive Stress ◽  
Energy Absorption ◽  
Wall Thickness ◽  
Syntactic Foam ◽  
Radius Ratio ◽  
Butadiene Rubber ◽  
Syntactic Foams ◽  
Compressive Properties

This research focuses on the effect of rejected nitrile butadiene rubber (rNBR) gloves particles reinforced epoxy macrospheres (EM) on the physical properties and compressive stress of syntactic foam. Adding rNBR particles on the surface of macrospheres can increase the energy absorption as a result of improving the compressive properties of syntactic foam. Three types of macrospheres have been produced for the fabrication of syntactic foam, namely EM without rNBR, 1-layer rNBR-EM and 2-layer rNBR-EM. The results showed that increased rNBR particles layer on macrospheres has increased the wall thickness, and reduced the radius ratio of macrospheres as well as increased the density of syntactic foams. The compressive strength and modulus of syntactic foam with 2-rNBR-EM increased compared to the syntactic foams of 1-rNBR-EM and EM without rNBR. In addition, the toughness of the 2-rNBR-EM increased compared to the syntactic foams of 1-rNBR-EM and EM without rNBR.

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