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.

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.

S082015 Development of Non-Destructive Evaluation Method for Heat Resistance of TBC on Gas Turbine Blade

2012 ◽  
Vol 2012 (0) ◽  
pp. _S082015-1-_S082015-4
Author(s):  
Takayuki OZEKI ◽  
Tomoharu FUJII ◽  
Eiji SAKAI ◽  
Tetsuo FUKUCHI ◽  
Norikazu FUSE
Keyword(s):  
Heat Resistance ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Evaluation Method ◽  
Gas Turbine Blade ◽  
Non Destructive Evaluation ◽  
Non Destructive

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

Comparison of NDE techniques for assessing mechanical properties of unjointed and finger-jointed lumber

Holzforschung ◽  
2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Tobias Biechele ◽  
Ying Hei Chui ◽  
Meng Gong
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Black Spruce ◽  
Correlation Coefficients ◽  
Bending Stiffness ◽  
Strength Prediction ◽  
Finger Joints ◽  
Non Destructive Evaluation ◽  
Non Destructive ◽  
Structural Lumber

Abstract Non-destructive evaluation (NDE) methods are common for grading structural lumber with static bending as the traditional NDE method for strength. More recently, longitudinal and transverse vibration techniques have also been proposed for grading lumber. In this study, unjointed and finger-jointed sawn lumber has been evaluated by these traditional and relatively new NDE methods. In total, 188 pieces of 38 mm×89 mm black spruce lumber were tested. Of these, 40 were unjointed, 47 had 2–3 finger joints, and 101 had 5–7 finger joints. The main objective was to evaluate the reliability of the various NDE techniques in predicting the bending stiffness and tensile strength of finger-jointed lumber with different number of finger joints. Results show that all NDE methods provide stiffness values of unjointed and finger-jointed lumber that correlate well with laboratory measured static bending stiffness with R2 values ranging from 0.76 to 0.97. Moreover, lumber with finger joints has lower bending stiffness than unjointed lumber. Based on the correlation coefficients, there is no evidence that finger joints affect the precision of the strength prediction by NDE methods.

Quantitative non-destructive evaluation method for impact damage using eddy current pulsed thermography

2013 ◽  
Vol 54 ◽  
pp. 169-179 ◽  
Author(s):  
Wenwei Ren ◽  
Jia Liu ◽  
Gui Yun Tian ◽  
Bin Gao ◽  
Liang Cheng ◽  
...  
Keyword(s):  
Eddy Current ◽  
Evaluation Method ◽  
Impact Damage ◽  
Pulsed Thermography ◽  
Non Destructive Evaluation ◽  
Non Destructive
Sign in / Sign up

Export Citation Format

Share Document