scholarly journals A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Akira Shimamoto ◽  
Keitaro Yamashita ◽  
Hirofumi Inoue ◽  
Sung-mo Yang ◽  
Masahiro Iwata ◽  
...  
Keyword(s):  
Welded Joints ◽  
Electrical Resistance ◽  
Spot Welding ◽  
Evaluation Method ◽  
Welded Joint ◽  
Nondestructive Method ◽  
Nugget Diameter ◽  
Two Factors ◽  
Surface Electrical Resistance ◽  
Spot Welded

Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α. The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: RQuota, which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.

G0301104 Influence of Variation of Nugget Diameter and Spot Welding Location on Fatigue Life of Spot Welded Joint

2015 ◽  
Vol 2015 (0) ◽  
pp. _G0301104--_G0301104-
Author(s):  
Masaki WASHIO ◽  
Chihiro TAKATUSUKA ◽  
Noboru TOMIOKA ◽  
Akifumi OKABE
Keyword(s):  
Fatigue Life ◽  
Spot Welding ◽  
Welded Joint ◽  
Nugget Diameter ◽  
Spot Welded

A Non-Destructive Evaluation Method: Measuring the Fixed Strength of Spot Welded Joint Points by Surface Electric Resistivity

2010 ◽  
Author(s):  
Akira Shimamoto ◽  
Keitaro Yamashita ◽  
Hirofumi Inoue ◽  
Sung-mo Yang ◽  
Masahiro Iwata ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Spot Welding ◽  
Evaluation Method ◽  
Welded Joint ◽  
Electric Resistivity ◽  
Electric Resistance ◽  
Non Destructive Evaluation ◽  
Nugget Diameter ◽  
Zinc Plating ◽  
Non Destructive

Destructive tests are generally applied for evaluating fixed strength of spot welding nuggets on zinc plating steel, which is swidely used as the primary automobile structural material. Destructive tests, however, are expensive and time consuming. This paper discusses a non-destructive method for evaluating of welded joints fixed strength by utilizing surface electric resistance. A nugget tester has developed by authors for this purpose. The non-destructive method focuses on surface electric resistance decreasing rate; α, and effect of the corona bond. Nugget diameter is estimated by RQuota calculated from variation of resistance and constant representing the area of the corona bond. Since maximum tensile strength is correlated with the nugget diameter, it is inferred from the estimated nugget diameter.

Ultrasonic Nondestructive Testing on False Welding Joint of Spot Welding for 00Cr18Ni10N Stainless Steel

2013 ◽  
Vol 662 ◽  
pp. 366-371
Author(s):  
Yong Zhang ◽  
Zong Fang Liu ◽  
Hong Xia Xie ◽  
Lian Zhi Guo
Keyword(s):  
Stainless Steel ◽  
Nondestructive Testing ◽  
Welded Joints ◽  
Spot Welding ◽  
Welded Joint ◽  
Test Method ◽  
Transmitted Wave ◽  
Ultrasonic Nondestructive Testing ◽  
Digital Oscilloscope ◽  
Spot Welded

00Cr18Ni10N stainless steel spot-welded joints were inspected by ultrasound in transmission mode under the water. By comparing and studying ultrasonic transmission wave signals of the spot welded joint of existing nugget and the false welded joint which were received by digital oscilloscope, we find that there are differences in degree of attenuation between multi transmitted wave and primary transmitted wave of two kinds of joints. The degree of attenuation of multi transmitted wave of false welded joint is obviously less than that of the joint with nugget. Therefore, false welded joint can be judged and identified through the degree of attenuation of multi transmitted wave relative to primary transmitted wave, and the dissection results verify the feasibility of this test method.

Assessment of Fatigue Life by FEMFAT on the Weld Configuration of Spot Welding

2008 ◽  
Vol 580-582 ◽  
pp. 625-628
Author(s):  
Bok Kyu Lim ◽  
Min Gun Kim ◽  
Ku Hyun Chung ◽  
Dong Youl Kim ◽  
Young Woo Choi
Keyword(s):  
Welded Joints ◽  
Spot Welding ◽  
Fatigue Behavior ◽  
Tensile Load ◽  
Design Criterion ◽  
Element Analysis ◽  
Single Spot ◽  
Welding Joints ◽  
The Stability ◽  
Spot Welded

The stability of plate structure is a very critical problem. The spot welding is practically designed by experiential decisions; so, it is inefficient and risks fatigue fracture. In real structure, multi-spot welded joints are more frequently used than single-spot welded joint. The fatigue behavior of multi-spot welded joints is different from that of single-spot welded joints. The fatigue lives of spot-welding specimen and multi points spot-welding structure are predicted using a FEMFAT 4.4e based on the linear finite element analysis. It is necessary to establish a reasonable and systematic design criterion for the long life design of the spot-welding body structure. In this study, relative location of spot welding was chosen as parameter and the stress distribution around the spot-welding joints’ subjected tensile load was numerically analyzed.

Influence of Welding Parameters on the Quality of Resistance Spot Welded Joints of DP600 Steels

2014 ◽  
Vol 635 ◽  
pp. 143-146 ◽  
Author(s):  
Ľuboš Kaščák ◽  
Emil Spišák ◽  
Ivan Gajdoš
Keyword(s):  
Automotive Industry ◽  
Automobile Industry ◽  
Welded Joints ◽  
Spot Welding ◽  
Welding Current ◽  
High Strength ◽  
Welding Parameters ◽  
Resistance Spot ◽  
Resistance Spot Welds ◽  
Spot Welded

Advanced high-strength dual-phase steel was developed specifically for automotive industry in order to benefit from its excellent formability and great crash absorption ability in comparison with conventional AHSS. Resistance spot welding is the dominant and effective method of joining metal sheets in automobile industry. After spot welding, important changes occur in mechanical and metallurgical properties of the spot welded areas and heat affected zones. The investigation into these changes is very important for safety, which depends on the strength of the welded joints. Weldability of the DP steel is one of the key factors governing its application in automotive industry. The influence of the primary welding parameters, especially welding current, on the weld quality was investigated by testing microhardness and tensile shear load bearing capacity of resistance spot welds of DP600 steel sheets.

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