Effects of heat input on welding buckling distortion by experimental measurement method

2016 ◽  
Vol 22 (5) ◽  
pp. 381-388 ◽  
Author(s):  
N. Guo ◽  
X.-Q. Yin ◽  
J. Liang ◽  
N. Ma
Keyword(s):  
Experimental Measurement ◽  
Heat Input ◽  
Measurement Method ◽  
Buckling Distortion

Low Heat Input Welding for Thin Steel Fabrication

2006 ◽  
Vol 22 (02) ◽  
pp. 105-109
Author(s):  
S.M. Kelly ◽  
R.P. Martukanitz ◽  
P. Michaleris ◽  
M. Bugarewicz ◽  
T. D. Huang ◽  
...  
Keyword(s):  
Laser Beam ◽  
Heat Input ◽  
Arc Welding ◽  
Process Development ◽  
High Heat ◽  
Hybrid Laser Arc Welding ◽  
Thin Steel ◽  
High Heat Input ◽  
Time Distortion ◽  
Buckling Distortion

As thinner members are used in marine construction, the use of conventional joining techniques results in significant angular and buckling distortion due to the inherent high heat input with these processes. Several low heat input alternatives, including laser beam, gas metal arc, and hybrid laser arc welding, are explored. The paper focuses on process development, real time distortion measurements, and implementation of these processes.

A new method for M-integral experimental evaluation

2012 ◽  
Vol 22 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Hong Zuo ◽  
Yu-hong Feng
Keyword(s):  
Stress Distribution ◽  
Nondestructive Evaluation ◽  
Experimental Measurement ◽  
Measurement Method ◽  
Evaluation Method ◽  
Specimen Geometry ◽  
Related Integral ◽  
Integral Contour ◽  
M Integral ◽  
Distribution Assumption

In this article, the experimental measurement method of M-integral is investigated. Through the detailed analysis to the nondestructive evaluation method of J- and M-integrals suggested by King and Herrmann, it is found that the specimen geometry which they selected and the corresponding clamping mode in their test exists a conflict with the stress distribution assumption on the integral contour. The formulas they proposed cannot represent the selected specimen geometry and the related integral contours. To avoid this conflict, a new experimental measurement method and a simper specimen style is proposed in this study. According to the method, the M-integral is nondestructive evaluated experimentally through the new specimen and the new clamping mode.

Low Heat Input Welding for Thin Steel Fabrication

2005 ◽  
Author(s):  
S. M. Kelly ◽  
R. P. Martukanitz ◽  
P. Michaleris ◽  
M. Bugarewicz ◽  
T. D. Huang ◽  
...  
Keyword(s):  
Laser Beam ◽  
Heat Input ◽  
Arc Welding ◽  
Process Development ◽  
High Heat ◽  
Hybrid Laser Arc Welding ◽  
Thin Steel ◽  
High Heat Input ◽  
Time Distortion ◽  
Buckling Distortion

As thinner members are used in marine construction, the use of conventional joining techniques result in significant angular and buckling distortion due to the inherent high heat input with these processes. Several low heat input alternatives, including laser beam, gas metal arc, and hybrid laser-arc welding are explored. The paper focuses on process development, real time distortion measurements and implementation of these processes.

A Predictive Technique for Buckling Analysis of Thin Section Panels Due to Welding

1996 ◽  
Vol 12 (04) ◽  
pp. 269-275
Author(s):  
Panagiotis Michaleris ◽  
Andrew DeBiccari
Keyword(s):  
Numerical Analysis ◽  
Heat Input ◽  
Large Scale ◽  
Three Dimensional ◽  
Analytical Models ◽  
Two Dimensional ◽  
Critical Buckling Load ◽  
Analysis Technique ◽  
Panel Thickness ◽  
Buckling Distortion

This paper presents an efficient and effective numerical analysis technique for predicting welding-induced buckling. The technique combines three-dimensional structural analyses with two-dimensional welding simulations. Implementation of the technique can determine the appropriate welding conditions under which the design critical buckling load is not exceeded. Experimental results obtained from small-and large-scale mock-up panels are used to confirm the predictions of the analytical models, The paper concludes with a study of the effects of heat input (weld size), panel size, and panel thickness on buckling distortion.

Practical Welding Techniques to Minimize Distortion in Lightweight Ship Structures

2005 ◽  
Author(s):  
C. Conrardy ◽  
T. D. Huang ◽  
D. Harwig ◽  
P. Dong ◽  
L. Kvidahl ◽  
...  
Keyword(s):  
Best Practices ◽  
Heat Input ◽  
Steel Structures ◽  
Welding Distortion ◽  
Manufacturing Cost ◽  
Welding Operation ◽  
Welding Heat Input ◽  
Distortion Control ◽  
Thin Steel ◽  
Buckling Distortion

The trend in both military and commercial shipbuilding is the increased use of thin steel to reduce weight and improve performance. Complex panel structures have thickness transitions for weight and structural optimization with multiple inserts ranging from 5 to 45 mm. Welding practices developed for thicker plate can result in significant out-of-plane distortion when applied to thin-plate structures. Buckling distortion of complex lightweight panels has resulted in a significant negative effect on manufacturing cost and production throughput, limiting the shipbuilders’ ability to produce innovative ship designs. High fitting and welding costs are the consequence of this large welding distortion. This problem is exacerbated as the fairness requirements are tightened. New methods are needed to control distortion when welding thinner materials. To tackle the distortion problems, in 2002 Northrop Grumman Ship Systems initiated a multiyear program to develop distortion-control technology for complex panels. This paper reports the results of a study to develop “best practices” for welding of lightweight structures. Control of welding distortion for thin structures requires control of each welding operation from butt-welding of plates through to unit assembly. A general philosophy was applied to minimize welding heat input while maximizing restraint during unit construction. To achieve this, the following techniques were evaluated: * Increasing restraint during each welding operation, * Improving fitting practice, * Weld sequencing and, * Minimizing welding heat input. * Additionally, an active distortion mitigation approach, known as Transient Thermal Tensioning, was investigated for reduction of buckling distortion during thin-panel longitudinal stiffener welding. A series of tests were performed to evaluate various distortion control approaches and to optimize production processes. The culmination of the project will involve demonstrating best practices in the production of thin steel structures. A plan is also being developed for implementing the most advantageous approaches into production.

Weld Modeling of Thin Structures With VFT Software

2004 ◽  
Author(s):  
Y. P. Yang ◽  
F. W. Brust ◽  
A. Ezeilo ◽  
N. McPherson
Keyword(s):  
Heat Input ◽  
Butt Joint ◽  
Welding Distortion ◽  
Fabrication Technology ◽  
Thin Structures ◽  
Plate Specimen ◽  
Modeling Software ◽  
Sensitivity Studies ◽  
And Control ◽  
Buckling Distortion

Virtual fabrication technology (VFT) weld modeling software has been mainly used in thick-structure welding simulation. Recently both U. S. and European shipyards have shown strong interests in using the software to predict and control welding distortion of thin-plate ship panels. It is more complicated to simulate the welding of thin structures than thick structures because buckling distortion often occurs during the welding of thin structures. To evaluate the effectiveness of VFT for predicting distortion in thin structures, a bead-on-plate specimen, a butt joint of two large plates, and a long T stiffener were analyzed with VFT welding modeling software. By comparing the predicted distortions with those obtained by measurement, it was found that VFT can accurately predict welding-induced distortions of thin structures. Sensitivity studies show that pre-deformation induced by upstream fabrication processes and heat input are important factors influencing predicted distortions. Both distortion trends and magnitudes for thin structures are influenced by pre-deformation and heat input.

Practical Welding Techniques to Minimize Distortion in Lightweight Ship Structures

2006 ◽  
Vol 22 (04) ◽  
pp. 239-247 ◽  
Author(s):  
C. Conrardy ◽  
T.D. Huang ◽  
D. Harwig ◽  
P. Dong ◽  
L. Kvidahl ◽  
...  
Keyword(s):  
Best Practices ◽  
Heat Input ◽  
Steel Structures ◽  
Welding Distortion ◽  
Manufacturing Cost ◽  
Welding Operation ◽  
Welding Heat Input ◽  
Distortion Control ◽  
Thin Steel ◽  
Buckling Distortion

The trend in both military and commercial shipbuilding is the increased use of thin steel to reduce weight and improve performance. Complex panel structures have thickness transitions for weight and structural optimization with multiple inserts ranging from 5 to 45 mm. Welding practices developed for thicker plate can result in significant out-of-plane distortion when applied to thin-plate structures. Buckling distortion of complex lightweight panels has resulted in a significant negative effect on manufacturing cost and production throughput, limiting the shipbuilders' ability to produce innovative ship designs. High fitting and welding costs are the consequence of this large welding distortion. This problem is exacerbated as the fairness requirements are tightened. New methods are needed to control distortion when welding thinner materials. To tackle the distortion problems, in 2002 Northrop Grumman Ship Systems initiated a multiyear program to develop distortion-control technology for complex panels. This paper reports the results of a study to develop "best practices" for welding of lightweight structures. Control of welding distortion for thin structures requires control of each welding operation from butt welding of plates through to unit assembly. A general philosophy was applied to minimize welding heat input while maximizing restraint during unit construction. To achieve this, the following techniques were evaluated: increasing restraint during each welding operation, improving fitting practice, weld sequencing, and minimizing welding heat input. Additionally, an active distortion mitigation approach, known as transient thermal tensioning, was investigated for reduction of buckling distortion during thin-panel longitudinal stiffener welding. A series of tests were performed to evaluate various distortion control approaches and to optimize production processes. The culmination of the project will involve demonstrating best practices in the production of thin-steel structures. A plan is also being developed for implementing the most advantageous approaches into production.

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