Dissertation > Excellent graduate degree dissertation topics show

The Influence of Welding Residual Stress and Deformation on Plastic Deformation Behavior of Tube Hydroforming

Author: HuangZuo
Tutor: FangHongYuan
School: Harbin Institute of Technology
Course: Materials Processing Engineering
Keywords: tailor-welded tube hydroforming residual stress angular distortion finite element simulation
CLC: TG404
Type: Master's thesis
Year: 2012
Downloads: 32
Quote: 0
Read: Download Dissertation


Tailor-welded tube has been widely used in the field of hydroforming technique,for such advantages as maintaining the structural integrity, optimizing distributionof materials, reducing weight and improving quality. However, current studies onhydroforming of tailor-welded tube are mainly focusing on distribution of wallthickness after forming process, regular pattern of welding line and applications oftailor-welded tube. There is no systematic analysis on the influence of residual stressand deformation around the welding line, which is critical to tailor-welded tubehydroforming process. These factors impede the development of hydroformingpossesses of tailor-welded tube seriously.Welding residual stress, deformation and angular distortion were firstly studiedby finite element simulation, the hydroforming processes of normal andtailor-welded tube were simulated relatively. Then, the influence of each factor wasgiven to conduct tailor-welded hydroforming theoretically.Using304stainless steel plate to measure actual temperature contrasting withthe simulation results, accurate convection heat transfer coefficients of stainlesssteel and air were determined, my which the veracity of simulation can be ensured.Mechanical properties of the heat affected zone (HAZ) were obtained by thermalsimulation method. Mechanical properties of the welding line were studies usingplate welding and tensile test. All these experiemental resules can make sure that thefinite element simulation can be conducted successfully.Finite element code Marc was used to model the normal hydroforming process,evolutions of stress and strain were studied at the preliminary forming, paster andunloading stage. The largest plastic deformation, which increased and shift tocentral plane of symmetry with the tube bulging, was located at the junctionbetween bulging and transition region at the preliminary forming stage. Moreover,circumferential tensile stress was the largest at the expanded zone and increaseduntil the end of preliminary forming stage. The circumferential plastic deformationwas a constant, the feed along the axis compensated the circumferential tensile,which transformed to compressive stress finally. The stress on the tube was nearly at0when the unloading stage finished.Influence of welding angular distortion and residual stress on tailor-weldedtube hydroforming were studied during the numerical simulation process. Thebending moment caused by the welding angular distortion could be eliminatedentirely, because the region of angular distortion is too small to create enoughbending moment. So the welding line transformed to concave after bulging. The major welding residual tensile stress at the weld toe integrated with the bulgingtensile stress generated the biggest circumferential tensile stress at the weld toe,which is the vulnerable zone during the tailor-welded tube hydroforming.

Related Dissertations

  1. Study of Mechanism Using Two-Direction Pre-Stress to Control Welding Distortion and Hot Cracking,TG404
  2. Numerical Simulation and Experiment on Hydroforming of Cups with Controllable Radial Pressure,TG386
  3. Research rotodyne cutting damage yuan formation mechanism of high-voltage driver,TJ811
  4. Residual Stress Research of the Laminates of Integral Multilayer-Wrapped Pressure Vessel,TH49
  5. Research on VSR Equipment Based on Spectral Analysis Method,TG156.92
  6. Martensitic Transformation Crystallography and Finite Element Simulation of Microstructure in Steels,TG142.24
  7. Numerical Simulation of Deformation in Low Carbon and /HSLA Thin Plate Welding,TG404
  8. Optimization of Machining Parameters of the Mating Surfaces of the Large Power Low Stress and Experimental Research,TG61
  9. 3d Finite Element Simulation of Rail Wheel Forming Process,U260.331.1
  10. X-ray diffraction analysis of a single crystal nickel base alloy residual stress AM1,TG115.22
  11. Pipeline circumferential excitation calculation method of magnetic flux leakage,TG115.284
  12. Metal plate surface electromagnetic ultrasonic flaw detection technology research,TG115.284
  13. Welding residual stress on LNG ship tank bulkhead fatigue life,U671.83
  14. Butt welding of hull shapes Numerical Simulation and Optimization,U671.8
  15. Research on Characteristics of Two-layer Cantilever Piezoelectric Energy Harvester,TN384
  16. The Key Technology Research of Ship Deformation Condition and Prediction,TP274
  17. High-speed rail switch rail longitudinal experimental study and finite element analysis of residual stress,U213.6
  18. Research on the Influence of 3d Electric Field on the Excitability of the Optic Nerve,R318.0
  19. Characteristics and Experiment Study on Residual Stress Induced by Controlled Laser Peening,TN249
  20. Evolution of Shear Band, Free Volume and Hardness of as Rolled Zr-based Bulk Metallic Glasses,TG339
  21. Effect of the Rubbing and Wearing Behavior of Steel Rail by Ultrasonic Peening,TG115.58

CLC: > Industrial Technology > Metallurgy and Metal Craft > Welding, metal cutting and metal bonding > Welding general issues > Stress and deformation of welded structures
© 2012 www.DissertationTopic.Net  Mobile