Numerical Simulation of Temperature Field during Laser Deep Penetration Welding

2011 ◽  
Vol 675-677 ◽  
pp. 865-867
Author(s):  
Ren Ping Wang ◽  
Y.P. Lei
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Computational Analysis ◽  
Energy Equation ◽  
304 Stainless Steel ◽  
Deep Penetration ◽  
Governing Equations ◽  
Laser Deep Penetration Welding ◽  
Deep Penetration Welding ◽  
Laser Keyhole Welding

A computational analysis is achieved during laser deep penetration welding. Multiple reflection and absorption are implemented simultaneously with the ray tracing technique in the keyhole. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Temperature field is achieved by numerical simulation. The laser keyhole welding experiments on 304 stainless steel sheet showed that the computational results agree well with experimental results.

Numerical Simulation of the Formation Process of the Keyhole in Laser Deep Penetration Welding

2010 ◽  
Vol 113-116 ◽  
pp. 1779-1781
Author(s):  
Ren Ping Wang ◽  
Yong Ping Lei ◽  
Yao Wu Shi
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Ray Tracing ◽  
Formation Process ◽  
Energy Equation ◽  
Deep Penetration ◽  
Governing Equations ◽  
Laser Deep Penetration Welding ◽  
Simulation Results ◽  
Deep Penetration Welding

In order to simulate accurately the formation process of the keyhole in laser deep penetration welding. Multiple reflection and Fresnel absorption are implemented simultaneously with the ray tracing technique in the keyhole. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Simulation results are compared with the experimental ones to verify its validity.

Keyhole Modeling during Laser Deep Penetration Welding

2010 ◽  
Vol 29-32 ◽  
pp. 252-257 ◽  
Author(s):  
Ren Ping Wang ◽  
Yong Ping Lei ◽  
Yao Wu Shi
Keyword(s):  
Mathematical Model ◽  
Software Package ◽  
Energy Equation ◽  
Deep Penetration ◽  
Governing Equations ◽  
Recoil Pressure ◽  
Laser Deep Penetration Welding ◽  
Simulation Results ◽  
Deep Penetration Welding ◽  
Ray Tracing Model

In order to accurately simulate the process of laser deep penetration welding, a mathematical model to describe laser deep penetration welding was developed by using the heat source derived from the ray-tracing model, and taking account into the effect of keyhole on welding pool. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Numerical simulation was conducted by FLUENT 6.3 software package. The simulation results show that the formation of keyhole in the weld is caused by recoil pressure.

Restoration and Enhancement of X-Ray Images of Molten Pool during Laser Deep Penetration Welding

2012 ◽  
Vol 201-202 ◽  
pp. 356-359
Author(s):  
Jun Bin Xiang ◽  
Xiang Dong Gao
Keyword(s):  
Molten Pool ◽  
High Speed ◽  
Blind Deconvolution ◽  
Welding Process ◽  
304 Stainless Steel ◽  
Deep Penetration ◽  
X Ray ◽  
Laser Deep Penetration Welding ◽  
Contrast Stretching ◽  
Deep Penetration Welding

Owing to a strong capability of penetration, the radiography can be used to observe and analyze the formation of a molten pool inside weldments during laser deep penetration welding. The shape of a molten pool and the thermal transmit of laser through keyhole can be monitored and analyzed in real-time. During a high-power fiber laser bead on plate welding of Type 304 stainless steel, a high-speed radiography camera was employed to capture the molten pool images. These captured X-ray images were degraded by the disturbance and noises from the welding process and radiography devices. This paper proposes an efficient arithmetic to restore and enhance the X-ray images of molten pools. The point spread function (PSF) of X-ray image degeneration was obtained through blind deconvolution, And the PSF was applied as a parameter to implement the constrained least squares filtering of X-ray image of a molten pool. Also, the X-ray image was enhanced by contrast stretching transformation. Experimental results showed that the proposed arithmetic of image restoration and enhancement could improve the quality of X-ray images efficiently and protrude the contour feature of a molten pool.

OCT-Einschweißtiefenüberwachung bei Unterdruck/OCT-based weld penetration monitoring at reduced ambient pressure – Influence of reduced ambient pressure on the OCT signal quality in laser deep penetration welding

2021 ◽  
Vol 111 (11-12) ◽  
pp. 863-868
Author(s):  
Thorsten Mattulat ◽  
Ronald Pordzik ◽  
Peer Woizeschke
Keyword(s):  
Penetration Depth ◽  
Ambient Pressure ◽  
Laser Beam Welding ◽  
In Situ Monitoring ◽  
Deep Penetration ◽  
Weld Penetration ◽  
Laser Deep Penetration Welding ◽  
Deep Penetration Welding ◽  
Non Destructive

Die optische Kohärenztomographie (OCT) erlaubt die zerstörungsfreie In-situ-Überwachung der Einschweißtiefe beim Laserstrahlschweißen. Für dieses Verfahren wird hier der Einfluss von verringerten Umgebungsdrücken auf die Messqualität untersucht. Es wird gezeigt, dass sich bei niedrigerem Umgebungsdruck deutlich größere Signalanteile aus dem Bereich des Bodens der Dampfkapillare zurückerhalten lassen. Auf diese Weise steigen die effektive Messfrequenz und die Erkennbarkeit von Änderungen der Einschweißtiefe.   Optical coherence tomography (OCT) enables non-destructive in-situ monitoring of the weld penetration depth during laser beam welding. For this technology, the influence of reduced ambient pressures on the measurement quality is investigated. It is shown that significantly larger signal components are obtained from the bottom of the vapor capillary at lower ambient pressure increasing the applicable measurement frequency and the detectability of changes in the weld penetration depth.

Sign in / Sign up

Export Citation Format

Share Document