scholarly journals Springback Analysis for Warm Bending of Titanium Tube Based on Coupled Thermal-Mechanical Simulation

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5044
Author(s):  
Guangjun Li ◽  
Zirui He ◽  
Jun Ma ◽  
Heng Yang ◽  
Heng Li
Keyword(s):  
High Reliability ◽  
Pure Titanium ◽  
Dimensional Accuracy ◽  
Element Model ◽  
Local Heat ◽  
Thickness Variation ◽  
Mechanical Working ◽  
Titanium Tube ◽  
Springback Angle ◽  
Springback Behavior

Titanium bent tubular parts attract extensive applications, thus meeting the ever-growing demands for light weight, high reliability, and long service life, etc. To improve bending limit and forming quality, local-heat-assisted bending has been developed. However, significant springback seriously reduces the dimensional accuracy of the bent tubular parts even under elevated forming temperatures, and coupled thermal-mechanical working conditions make springback behavior more complex and difficult to control in warm bending of titanium tubular materials. In this paper, using warm bending of thin-walled commercial pure titanium tube as a case, a coupled thermal-mechanical finite element model of through-process heating-bending-unloading is constructed and verified, for predicting the springback behavior in warm bending. Based on the model, the time-dependent evolutions of springback angle and residual stress distribution during thermal-mechanical unloading are studied. In addition, the influences of forming temperature and bending angle on springback angle, thickness variation, and cross-section flattening of bent tubes are clarified. This research provides a fundamental understanding of the thermal-mechanical-affected springback behavior upon local-heat-assisted bending for improving the forming accuracy of titanium bent tubular parts and structures.

Characteristics of Rotary Draw-Bent Tubes for the Hydroforming

2011 ◽  
Vol 213 ◽  
pp. 320-324
Author(s):  
Byeong Don Joo ◽  
Jeong Hwan Jang ◽  
Hyun Jong Lee ◽  
Young Hoon Moon
Keyword(s):  
Cross Section ◽  
Structural Strength ◽  
Dimensional Accuracy ◽  
Thickness Variation ◽  
Important Process ◽  
Rotary Draw Bending ◽  
Higher Dimensional ◽  
Bending Process ◽  
Geometric Size ◽  
Draw Bending

Hydroformed parts have higher dimensional accuracy, structural strength, and dimensional repeatability. The pre-bending process is an important process for the successful hydroforming in the case where the perimeter of the blank is nearly the same as that of final product. At initial pre-bending stage, the variations of wall thickness and cross-section have effects on the accuracy of final products and quality. Because of a relatively excellent productive velocity, geometric size precision and reliance of product qualities, rotary draw bending is widely used. This study shows the bendability such as cross-section ovality, springback ratio and thickness variation in the various conditions of materials.

Experimental Characterization and Finite Element Modeling of Film Capacitors for Automotive Applications

2016 ◽  
Author(s):  
D. Croccolo ◽  
T. M. Brugo ◽  
M. De Agostinis ◽  
S. Fini ◽  
G. Olmi
Keyword(s):  
Finite Element ◽  
Mechanical Response ◽  
High Reliability ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Life Time ◽  
Element Model ◽  
Image Correlation ◽  
Thermal Loads ◽  
Mechanical Shock

As electronics keeps on its trend towards miniaturization, increased functionality and connectivity, the need for improved reliability capacitors is growing rapidly in several industrial compartments, such as automotive, medical, aerospace and military. Particularly, recent developments of the automotive compartment, mostly due to changes in standards and regulations, are challenging the capabilities of capacitors in general, and especially film capacitors. Among the required features for a modern capacitor are the following: (i) high reliability under mechanical shock, (ii) wide working temperature range, (iii) high insulation resistance, (iv) small dimensions, (v) long expected life time and (vi) high peak withstanding voltage. This work aims at analyzing the key features that characterize the mechanical response of the capacitor towards temperature changes. Firstly, all the key components of the capacitor have been characterized, in terms of strength and stiffness, as a function of temperature. These objectives have been accomplished by means of several strain analysis methods, such as strain gauges, digital image correlation (DIC) or dynamic mechanical analysis (DMA). All the materials used to manufacture the capacitor, have been characterized, at least, with respect to their Young’s modulus and Poisson’s ratio. Then, a three-dimensional finite element model of the whole capacitor has been set up using the ANSYS code. Based on all the previously collected rehological data, the numerical model allowed to simulate the response in terms of stress and strain of each of the capacitor components when a steady state thermal load is applied. Due to noticeable differences between the thermal expansion coefficients of the capacitor components, stresses and strains build up, especially at the interface between different components, when thermal loads are applied to the assembly. Therefore, the final aim of these numerical analyses is to allow the design engineer to define structural optimization strategies, aimed at reducing the mechanical stresses on the capacitor components when thermal loads are applied.

scholarly journals Investigation on Springback Behavior of Cu/Ni Clad Foils during Flexible Die Micro V-Bending Process

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 892 ◽  
Author(s):  
Chuanjie Wang ◽  
Shan Wang ◽  
Shuting Wang ◽  
Gang Chen ◽  
Peng Zhang
Keyword(s):  
Compressive Stress ◽  
Thin Sheet ◽  
Interface Layer ◽  
Interactive Effects ◽  
Bending Process ◽  
Micro Parts ◽  
Increasing Demand ◽  
Flexible Die ◽  
Springback Angle ◽  
Springback Behavior

With the increasing demand for micro parts using metal laminates in modern production, the manufacturing processes of thin sheet parts have been elevated. However, it is difficult to predict the deformation behavior with miniaturization because of size effects in micro-scale. In this study, the flexible die micro V-bending behavior of Cu/Ni clad foils was investigated. The bending experiments with three different punch angles and Cu/Ni clad foils under different annealed temperatures were performed. The results show that the springback angle increases with the increase of bending angle and annealing temperature. The placement of Cu/Ni clad foils induced compressive stress results in the more obvious thinning of thickness and decreasing of springback angle. The interactive effects of the distribution of deformation zones and compressive stress induced by the interface layer result in the springback behavior of Cu/Ni clad foils during the flexible die micro V-bending process.

Effect of Combined Rolling Processes on Structure and Mechanical Properties of Pure Titanium Rods

2010 ◽  
Vol 667-669 ◽  
pp. 161-166 ◽  
Author(s):  
Nikolay Lopatin ◽  
Grigoriy Diakonov ◽  
Olga Pleshakova
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Microstructure Evolution ◽  
Strain State ◽  
Pure Titanium ◽  
Element Model ◽  
Warm Rolling ◽  
Shape Rolling ◽  
Commercially Pure ◽  
The Finite Element Model

This article focuses on the effect of combine rolling processes on structure and mechanical properties of the commercially pure Ti rods. The finite element model had being made. The analysis of strain state at the screw and shape rolling was done. The analysis of microstructure evolution at the warm rolling was completed.

scholarly journals Formation and Determination of Psychometric Features Pertaining to Happiness Inventory

2016 ◽  
Vol 9 (6) ◽  
pp. 55
Author(s):  
Abdollah Shafiabady ◽  
Maryam Gholamzadeh Jofreh ◽  
Ali Delavar ◽  
Masoumeh Esmaeeli
Keyword(s):  
Data Analysis ◽  
High Reliability ◽  
Reliability And Validity ◽  
Element Model ◽  
Inventory Data ◽  
The Way

There have been a lot of arguments about the way happiness can be measured. Multiple questionnaires and inventories are used for this purpose. The present study seeks to formulate and determine psychometric features (stability and reliability) and a confirmative factor-based structure is proposed. B.A. and M.A. students of Ahvaz Azad University in year 94–95 participate in this study. 350 students were randomly selected and data was collected using happiness inventory. Data analysis revealed the intended inventory consists of 5 factors and 43 elements. This inventory enjoys relatively high reliability and validity. The confirmative factor – based structure also showed the inventory has a five element model.  

Three-Dimensional Finite Element Modeling of Hard Turning Processes

Manufacturing ◽  
2003 ◽  
Author(s):  
T. D. Marusich ◽  
R. J. McDaniel ◽  
S. Usui ◽  
J. A. Fleischmann ◽  
T. R. Kurfess ◽  
...  
Keyword(s):  
Finite Element ◽  
Hard Turning ◽  
Metal Cutting ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Tool Material ◽  
Dimensional Accuracy ◽  
Element Model ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Hard turning processes promise affordable fabrication of machined components with high dimensional accuracy requirements. In an effort to achieve the desired economics a vast array of process variables must be considered including tool material, geometry, edge preparation, wear, speed and feed selection, while maintaining part quality. One method to reduce the number of necessary experiments is through accurate and reliable modeling. A three-dimensional finite element model is presented which includes fully adaptive unstructured mesh generation, tight thermo-mechanically coupling, deformable tool-chip-workpiece contact, interfacial heat transfer across the tool-chip boundary, momentum effects at high speeds and constitutive models appropriate for high strain rate, finite deformation analyses. The model is applied to nose turning of hardened steel workpieces, HRc 60. Metal cutting tests are performed, cutting forces collected, and validation comparison is made.

The Application of Slip Joint Use in Space Frame Structure for Vehicle

2013 ◽  
Vol 423-426 ◽  
pp. 1944-1947
Author(s):  
Sheng Yun Lee ◽  
Ting Hao Cheng ◽  
Yu Ting Lin
Keyword(s):  
Dimensional Accuracy ◽  
Element Model ◽  
Frame Structure ◽  
Poor Control ◽  
Space Frame ◽  
Space Frames ◽  
The Common ◽  
The Finite Element Model ◽  
Joint Method ◽  
Space Frame Structure

The purpose of this paper is to analysis the finite element model of joint methods for chassis space frames of vehicles. Common tee-joint often have poor control of dimensional accuracy. The analysis includes the common tee-joint and new joint method. Although the new joint method will increase in weight a little and easily adjust the accuracy of space frame, it will also improve the connection strength.

Crashworthiness Analysis of Mobile Hard Disk under Different Drop Angles

2011 ◽  
Vol 697-698 ◽  
pp. 681-685
Author(s):  
Shu Yi Yang ◽  
D.S. Liu ◽  
Ji Yun Zhao ◽  
H. Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Hard Disk ◽  
Element Model ◽  
Mechanical Working ◽  
Crashworthiness Analysis

Mobile hard disk is very sensitive to vibration because of unique mechanical working and the complexity of components. In view of inner structure and complying with quality equivalent principle, a 2.5 inch mobile hard disk finite element model is established based on ANSYS/LS-DYNA. The crashworthiness evaluate index is analyzed and set forward. The influence of drop angle is analyzed through simulation. In theoretically, the results are proven to be fundamental method of crashworthiness analysis, evaluation and design for mobile hard disk.

Simulation and Optimization of U-Bending Springback Using Genetic Algorithms

2011 ◽  
Vol 69 ◽  
pp. 17-22
Author(s):  
Lei Chen
Keyword(s):  
Genetic Algorithms ◽  
Optimization Technique ◽  
Dimensional Accuracy ◽  
Element Model ◽  
Optimization Techniques ◽  
Simulation And Optimization ◽  
Sheet Metal Parts ◽  
Blank Holding Force ◽  
Elastoplastic Materials ◽  
Updated Lagrangian

Springback during unloading affects the dimensional accuracy of sheet metal parts. This paper proposes a finite element model to predict springback with contact evolution between the sheet and dies. The underlying formulation is based on updated Lagrangian elastoplastic materials model. The solutions validated with experimental data of NUMISHEET’93 show more accurately. The effects of the variable blank holding force (VBHF) on springback results are investigated based on genetic algorithms (GAs) for the determination of the parameters in blank holding operations. It has been found that the GAs based optimization technique is very effective in solving this kind of problem. The difficulty of choosing correct starting values for the constants in the traditional optimization techniques has been completely overcome and the GAs technique provides a better chance to converge to the global minimum.

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