مقاله جوشکاری Study of Forward Method on Imaging of Nugget in Resistance Spot Welding
مقاله جوشکاری با عنوان : Study of Forward Method on Imaging of Nugget in Resistance Spot Welding
Wenbo Xuan, Zhen Luo, Yang Li, Naifeng Fan
چکیده:
Inversion imaging of nugget in resistance spot
welding (RSW) is a new developing method of monitoring the
welding quality in RSW in recent years, which is based on the
rapid developments of the inverse problems in mathematics
and physics. This paper does some research on the forward
problem of inversion imaging of nugget and establishes the
forward model of RSW on the basis of the forward theory and
the electromagnetic field theory. And the soft wares of
MATLAB and ANSYS are used to simulate the
electromagnetic field of the forward model. The model’s
reliability is verified by comparing the experimental results
with the simulated results, which makes a good foundation for
the inversion imaging of nugget in RSW.
THE FINITE ELEMENT MODELING OF RESISTANCE SPOT WELDING
مقاله شبیه سازی جوشکاری مقاومتی نقطه ای با عنوان :
THE FINITE ELEMENT MODELING OF RESISTANCE SPOT WELDING
قسمتی از چکیده:
THE FINITE ELEMENT MODELING OF RESISTANCE SPOT WELDING
- V. Gohil *, S. M. Patel #
ABSTRACT
Resistance spot welding process is the most significant joining process in the automobile industry due to its high speed and suitability for automation. One of the recent demands in the automobile industry is to reduce the vehicle weight so as to improve the fuel efficiency and to meet this requirement, aluminium alloys is being considered as an important alternative for auto-body material. The vehicle corrosion problem can also be squarely dealt with. However, unlike resistance spot welding of steel, joining of aluminium through the same process has met with serious difficulties, because of faster deterioration of electrodes. High electrical and thermal conductivity, high shrinkage during solidification and the presence of natural oxide coating are some of the features that make spot welding process of aluminium alloys markedly different. At a very high temperature aluminium chemically reacts with copper alloy (electrode material). Subsequently random chipping-off of material from the electrode faces takes place and it results in electrode wear. Further, the electrode life reduces drastically when spot welding aluminium alloys. In terms of weldability, this is an extreme negative point since weldability for automobile use is greatly dictated by electrode tip life.
مقاله جوشکاری Ultrasonic spot welded AZ31 magnesium alloy: Microstructure, texture, and lap shear strength
مقاله جوشکاری با عنوان : Ultrasonic spot welded AZ31 magnesium alloy: Microstructure, texture, and lap shear strength
V.K. Patel, S.D. Bhole n, D.L. Chen
چکیده:
The structural application of ultra-lightweight magnesium alloys inevitably involves welding and
joining. A solid-state welding – ultrasonic spot welding (USW) – was conducted on AZ31B-H24 Mg
alloy sheet by varying a key parameter of welding energy in this study, aiming to identify the changes
in the microstructure, crystallographic texture, and lap shear tensile strength. The grain size was
observed to increase with increasing welding energy. Crystallographic texture determined via X-ray
diffraction showed a significant change that corresponded well to the change in the deformation and
recrystallization mechanisms of the Mg alloy. The lap shear strength first increased with increasing
energy input, reached the maximum value at a welding energy of 2000 J, then decreased. The welds
generally fractured along the joint interface when the welding energy was lower than 2000 J, while
fracture occurred at the periphery of the joint (button pull-out) for the samples made with an energy
input of higher than 2000 J.
مقاله جوشکاری FINITE ELEMENT MODELING OF RESISTANCE SPOT WELDING PROCESS
مقاله جوشکاری به عنوان :
FINITE ELEMENT MODELING OF RESISTANCE SPOT WELDING
PROCESS
P. Chigurupati*, B.K Chun, A. Bandar, W.T Wu
Scientific Forming Technologies Corporation
2545 Farmers Drive, Suite 200, Columbus, OH 43235, USA
چکیده:
ABSTRACT: Weld quality in Resistance Spot Welding is directly influenced by competing process transients. These
transients are caused by electrical, thermal, mechanical and metallurgical interactions. Controlling the process variables
such as current, clamping force and welding time requires good understanding of how these interactions evolve during
the welding process. In order to better understand the process and to control the final product quality in an efficient
manner, a comprehensive process model that can account for these multi physics phenomena is required. This paper
describes a general methodology that is used in the commercial Finite Element code, DEFORMTM to model the
resistance spot welding process incorporating all the basic mechanics of deformation, thermal, electrical and
microstructure models. Modeling process is illustrated using an example from the published literature. A detailed
discussion of the process mechanics based on the observed transients during various stages of the spot welding process
are presented. Model predictions on the thermal, mechanical and evolving microstructural phases during the welding
process are also discussed.
مقاله جوشکاری Modeling and Fuzzy Control of the Resistance Spot Welding Process
مقاله جوشکاری با عنوان : Modeling and Fuzzy Control of the Resistance Spot Welding Process
Xingqiao Chen, Keiiji Araki, Takeshi Miziiiio
چکیده :
This paper establishes a welding energy model and describes a hzzy adaptive process control
scheme for a resistance spot welding system.
For a welding system, it is not easy to measure with on-line the output, the nugget size, by usual
measuring method. And it is also difficult to control the welding process in real time . The paper
proposes a new method with input welding energy to estimate the nugget size and to reckon the
welding process. An optimal welding energy reference model is founded compared with different
input method of welding energy. A fizzy adaptive process control scheme with the model is also,
here, described to realize real time control and to improve control performance.
The results of simulation and experiments show that the reference model is effective on reducing
loss energy and prodiicing a sound nugget and the hzzy adaptive control scheme may obtain an
optimal control process for resistance spot welding