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Journal Article

Modeling of resistance spot weld nugget growth

01 Jan 1992-Welding Journal (American Welding Society)-Vol. 71, Iss: 2
TL;DR: In this paper, the weld nugget in resistance spot welding of Type 347 stainless steel was found, using finite element methods, to initiate in a ring shape at a distance from the electrode center.
Abstract: The weld nugget in resistance spot welding of Type 347 stainless steel was found, using f inite element methods, to initiate in a ring shape at a distance from the electrode center. The ring-like weld nugget expands inward and outward during the welding cycles. The welding current, electrode pressure and hold time affected the thermomechanical interactions of the welding process and changed the f inal nugget geometry. Also, when spot welding workpieces of unequal thicknesses, it was found that the weld nugget formed mostly in the thicker workpiece than in the thinner workpiece, and when spot welding dissimilar materials, the weld nugget formed more in the workpiece of lower thermal conductivity or higher electrical resistivity.
Citations
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Journal ArticleDOI
TL;DR: In this paper, a finite element analysis environment is used to evaluate the shape and size of weld nuggets and the effects of welding parameters on temperature of faying surface, which can assist in adjusting welding parameters so that costly experimental works can be avoided.

133 citations

Journal ArticleDOI
TL;DR: A 2D axisymmetric electro-thermo-mechanical finite element (FE) model was developed to study the effect of welding time and current intensity on nugget size in resistance spot welding process of AISI type 304L austenitic stainless steel sheets using ANSYS commercial software package.

94 citations

Journal ArticleDOI
TL;DR: In this paper, a coupled thermal-electrical-mechanical analysis was employed to predict the nugget development during resistance spot welding (RSW) of Al-alloys.
Abstract: This paper develops a model to predict the nugget development during resistance spot welding (RSW) of Al-alloys. The model employs a coupled thermal-electrical-mechanical analysis and accounts for phase change and convective transport in the weld pool. The contact area and the pressure distribution are determined from a coupled thermal ? mechanical model. The model calculates time varying interface pressure. The knowledge of interface pressure allows for accurate prediction of interfacial heat generation. Temperature-dependent thermal-electrical-mechanical properties are used. The predicted nugget shape and size agree well with experimental data. The proposed model can be applied to predict the effects of the welding parameters and the electrode shapes on the nugget development.

93 citations

Journal Article
TL;DR: In this article, a comprehensive analysis procedure has been developed to perform the incrementally coupled thermal-electrical-mechanical analysis to simulate the resistance spot welding process of aluminum alloys.
Abstract: A comprehensive analysis procedure has been developed to perform the incrementally coupled thermal-electrical-mechanical analysis to simulate the resistance spot welding process of aluminum alloys. Because aluminum has high thermal conductivity, low melting temperature and low yield strength, deformation resulting from resistance spot welding is expected to be more severe than for steel. Compared with most of the published work in this area, this paper takes into account the incremental changes in sheet-deformed shape, contact area and current density profile as well as large deformation effects. The present analysis procedures consider electrical contact resistivities to be not only functions of contact temperature but also functions of pressure. Joule heating at the contact surfaces is computed using an equivalent surface heat generation concept. This new procedure is suitable for analyzing many important parameters such as contact area changes, electrode movement and dynamic resistance, as well as other factors that contribute to weld quality such as weld size, weld indentation, sheet separation and weld residual stresses. It can also be used to study nugget development and analyze the mechanisms of electrode wear and weld cracking.

75 citations


Additional excerpts

  • ...δU = vτδεdV = sTδudS = δV (7) ρ δθ δθ θ...

    [...]

Journal ArticleDOI
TL;DR: In this paper, an electro-thermo-mechanical model is used to predict electrical potential, temperature and residual stress distributions during different stages of resistance spot welding, which is capable of considering the effects of welding parameters such as heat input and welding time on residual stress distribution.

74 citations

References
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Book
01 Jan 1979
TL;DR: In this paper, CARY this paper discusses the development of WELDING TECHNOLOGY in the last five years and discusses the 6th edition of his book, Modern WELDing Technology 6TH EDITION 6.
Abstract: MODERN WELDING TECHNOLOGY 4TH EDITION HARDCOVER BY. MODERN WELDING TECHNOLOGY 5TH EDITION HOWARD B CARY. DOWNLOAD MODERN WELDING TECHNOLOGY HOWARD B CARY. 5 DAYS MODERN WELDING TECHNOLOGY IN HELIOPOLIS CAIRO FROM. MODERN WELDING TECHNOLOGY 6TH EDITION MYPEARSONSTORE. RECENT DEVELOPMENTS IN WELDING TECHNOLOGY MAY 2006. MODERN WELDING TECHNOLOGY EDITION 5 BY HOWARD CARY. AMAZON COM CUSTOMER REVIEWS MODERN WELDING TECHNOLOGY. MODERN WELDING TECHNOLOGY HOWARD B CARY NHBS BOOK SHOP. WELDING PROCESSES NEWAGEPUBLISHERS COM. 9780131130296 MODERN WELDING TECHNOLOGY 6TH EDITION. MODERN WELDING TECHNOLOGY SEARCH AND DOWNLOAD. MODERN WELDING TECHNOLOGY GOOGLE BOOKS. CARY MODERN WELDING TECHNOLOGY PEARSON. MODERN WELDING TECHNOLOGY SCOTT HELZER 9780131130296. MODERN WELDING TECHNOLOGY EDITION 6 BY HOWARD B CARY. MODERN WELDING TECHNOLOGY CARY PDFSDOCUMENTS COM. MODERN WELDING TECHNOLOGY BOOK BY HOWARD B CARY. MODERN WELDING TECHNOLOGY 6TH EDITION HOWARD B CARY. MODERN WELDING TECHNOLOGY BOOK 2005 WORLDCAT ORG. MODERN WELDING TECHNOLOGY PDF DOWNLOAD PLAYCUBE ORG. MODERN WELDING TECHNOLOGY EBOOKDIG BIZ. MODERN WELDING INDUSTRIAL PROCESSES WELDING. WELDING TECHNOLOGY WELDING MESA COMMUNITY COLLEGE. MODERN WELDING TECHNOLOGY 6TH EDITION 9780131130296. MODERN WELDING TECHNOLOGY BOOK 2005 WORLDCAT ORG. 0131130293 MODERN WELDING TECHNOLOGY 6TH EDITION BY. MODERN WELDING TECHNOLOGY 2005 EDITION OPEN LIBRARY. MODERN WELDING TECHNOLOGY PROLIFIC CONSULTANT. MODERN WELDING TECHNOLOGY 6TH EDITION HOWARD B CARY. MODERN WELDING TECHNOLOGY BY HOWARD B CARY GOODREADS. MODERN WELDING TECHNOLOGY PEARSON SCHWEIZ AG. CARY AMP HELZER MODERN WELDING TECHNOLOGY 6TH EDITION. MODERN WELDING HOME PAGE. MODERN WELDING TECHNOLOGY OPEN LIBRARY. MODERN WELDING TECHNOLOGY VEIROL DE. MODERN WELDING TECHNOLOGY DOWNLOAD EBOOK PDF EPUB. WELDING WIKIPEDIA. MODERN WELDING TECHNOLOGY CH 13 21 22 AMP 25 WELDING. PDF EPUB DOWNLOAD MODERN ARC WELDING TECHNOLOGY EBOOK. MODERN WELDING TECHNOLOGY BOOK BY HOWARD B CARY 6. MODERN WELDING TECHNOLOGY MODERN WELDING TECHNOLOGY. MANUFACTURING ENGINEERING WIKIPEDIA. MODERN WELDING TECHNOLOGY DOWNLOAD EBOOK PDF EPUB. PDF EPUB DOWNLOAD MODERN WELDING TECHNOLOGY EBOOK. MODERN WELDING

432 citations


"Modeling of resistance spot weld nu..." refers background in this paper

  • ...The surface convection coefficient between the lateral surfaces and the air was specified equal to 9E-6 Btu/s in.(2) °F....

    [...]

Journal ArticleDOI
TL;DR: In this paper, a new mathematical treatment of the general problem of electrical heating of conductors has been developed, which gives, under appropriate conditions, a concise derivation of all the main results of the accepted theory; in addition it leads to three new conclusions.
Abstract: The experiments in part I on the behaviour of the contact between metals when large currents pass the interface have yielded results which cannot be explained by the classical theory of constriction resistances. In an attempt to provide an account of this anomalous behaviour a new mathematical treatment of the general problem of the electrical heating of conductors has been developed. This treatment gives, under the appropriate conditions, a concise derivation of all the main results of the accepted theory; in addition it leads to three new conclusions. First, it is shown that the general problem of finding the spatial distribution of the potential, the current, and the temperature within a medium whose thermal and electrical conductivities vary with temperature may be reduced to the corresponding problem with constant conductivities, and a simple numerical integration. Secondly, it is shown that the spatial distribution of the current within the conductor is independent of the thermal and electrical properties of the medium, and that it is unaltered by variation s of the total current passing. Finally, it is demonstrated that there are certain conditions under which a steady solution of the problem is impossible. For many conductors steady conditions are possible only when the current is below a certain critical value. If a current greater than this critical value is maintained the temperature will rise continuously, and eventually the process will be limited by some other phenomenon, for example, melting. The new treatment is applied to the calculation of the spatial distribution of current for a particular shape of conductor, one which is relevant to many resistance welding processes. The predictions agree accurately with experimental data obtained from the examination of a series of welds. The theory is then applied to the special case of the electrical contact between gold pieces and shown to offer an explanation of the anomalous behaviour mentioned above. Good agreement is demonstrated between the theoretical predictions and the experimental results.

145 citations

Journal ArticleDOI
TL;DR: The effect of passing an electric current through the interface between two contacting pieces of gold has been investigated, and it has been shown that the current can cause appreciable changes in the true area of contact between the surfaces as discussed by the authors.
Abstract: The effect of passing an electric current through the interface between two contacting pieces of gold has been investigated, and it has been shown that the current can cause appreciable changes in the true area of contact between the surfaces. This phenomenon has been studied by measuring the associated alterations in the constriction resistance. (This is the resistance caused by the constriction produced in the current stream as it passes through the tiny areas of contact between the metals.) It is shown that the response of the region of contact may be explained as a result of the heat generated in this resistance by the current. For any given current there is a certain critical degree of constriction through which it will just pass with ­out causing a permanent change in the contact region; if the current flows through a contact area which presents a constriction resistance greater than this critical value, then the heat generated will be sufficient to cause the yield pressure of the metal near the interface to fall, and the area of contact will increase accordingly. The critical constriction resistance associated with any current has been found to be inversely proportional to the magnitude of the current. The response of the contact region to short-duration pulses of current has been studied. The results show that the behaviour is independent of the length of the pulse in the range investigated (10 μ s to 10 ms). They also indicate that when a short pulse of current passes between the pieces of metal mechanical collapse will occur only if the current is sufficiently large to cause melting of the metal near the interface. It is possible to calculate the temperature in the contact region from the potential difference developed across the constriction. Calculations based on the accepted mathematical treatment indicate that mechanical collapse occurred in these experiments when the temperature at the interface was raised to about 950 °C. (This is significantly below the melting point of gold, 1063 °C.) This result was not supported by direct examination of the specimens, which showed clear evidence of melting whenever collapse occurred. It is suggested that the accepted mathematical treatment of constriction resistances may not be valid when the temperature approaches the melting point; and in part II a new treatment, which accounts for the observed results, is derived.

58 citations

Journal ArticleDOI
TL;DR: In this paper, the frictionless contact problem for an infinite elastic layer lying on a horizontal rigid plane is considered, where the external load is applied to the layer through a rigid stamp.

35 citations