Cross Weld Tensile Testing With Digital Image Correlation to Determine Local Strain Response

2021 ◽  
Author(s):  
William Siefert ◽  
James Rule ◽  
Boian Alexandrov ◽  
Jorge Penso ◽  
Michael P. Buehner
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Tensile Testing ◽  
Local Strain ◽  
Image Correlation ◽  
Strain Response

Cross Weld Tensile Testing With Digital Image Correlation to Determine Local Strain Response

2020 ◽  
Author(s):  
William Siefert ◽  
James Rule ◽  
Boian Alexandrov ◽  
Mike Buehner ◽  
Jorge A. Penso
Keyword(s):  
Tensile Strength ◽  
Digital Image Correlation ◽  
Tensile Test ◽  
Base Metal ◽  
Digital Image ◽  
Tensile Testing ◽  
Local Strain ◽  
Image Correlation ◽  
Weld Strength ◽  
Final Failure

Abstract Qualification for weld strength is typically accomplished using cross weld tensile testing. This style of testing only gives the global behavior of the welded joint and limited materials properties, such as elongation at failure and tensile strength of the material where final failure occurs. Qualification for welded structures usually requires the weldment fails in the base metal. Final failure in cross weld tensile tests in the base metal does not provide information about the actual weld metal and heat affected zone properties. There may be weaker points in the microstructure that cannot be identified in a global cross weld tensile test due to being constrained by surrounding microstructures. Additionally, the traditional cross weld tensile test does not quantify how strain accumulates and transfers in the microstructure at various loads. Using Digital Image Correlation (DIC) in combination with tensile testing, local strain of the various microstructures present across the weld was obtained for ferritic to austenitic dissimilar metal welds (DMW), as well as for a typical “matching” ferritic steel filler metal weld with a higher tensile strength than the base metal. This test also showed where and how strain accumulated and transferred during tensile loading of various welded microstructures. Local yield stresses of each region were also obtained. Obtaining such local properties provides insight into design and service limits of welded components in service.

Predicting strains in embedded reinforcement based on surface deformation obtained by digital image correlation technique

2021 ◽  
Author(s):  
Ali Mirzazade ◽  
Cosmin Popescu ◽  
Thomas Blanksvärd ◽  
Björn Täljsten
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Surface Deformation ◽  
Local Strain ◽  
Surface Strain ◽  
Image Correlation ◽  
Correlation Technique ◽  
Proposed Model ◽  
Structural Inspection ◽  
Semi Empirical

<p>This study is carried out to assess the applicability of using a digital image correlation (DIC) system in structural inspection, leading to deploy innovative instruments for strain/stress estimation along embedded rebars. A semi-empirical equation is proposed to predict the strain in embedded rebars as a function of surface strain in RC members. The proposed equation is validated by monitoring the surface strain in ten concrete tensile members, which are instrumented by strain gauges along the internal steel rebar. One advantage with this proposed model is the possibility to predict the local strain along the rebar, unlike previous models that only monitored average strain on the rebar. The results show the feasibility of strain prediction in embedded reinforcement using surface strain obtained by DIC.</p>

Study on Lüders Deformation in Welded Mild Steel Using Infrared Thermography and Digital Image Correlation

2012 ◽  
Vol 585 ◽  
pp. 82-86 ◽  
Author(s):  
N. Srinivasan ◽  
N. Raghu ◽  
B. Venkatraman
Keyword(s):  
Digital Image Correlation ◽  
Mild Steel ◽  
Infrared Thermography ◽  
Digital Image ◽  
Tensile Testing ◽  
Image Correlation ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Testing ◽  
Heterogeneous Deformation ◽  
Lüders Band

Studies on characterizing heterogeneous deformations in many materials under different loading conditions using imaging NDE techniques like Infrared thermography (IRT) and Digital image correlation (DIC) began in the last decade and have been reported by many researchers. This work aims in experimental investigation of one such heterogeneous deformation namely Lüders band phenomenon in welded IS 2062 E250-B mild steel during monotonic, uniaxial tensile testing using IRT and DIC. Also attempt has been made to study the generation of pre-yield microstrain in welded material. An understanding of nucleation and propagation of Lüders band in welded specimen is made based on temperature and strain changes.

scholarly journals Characterisation of weld heterogeneity through hardness mapping and miniature tensile testing

2015 ◽  
Vol 6 (3) ◽  
pp. 8 ◽  
Author(s):  
Jonas Bally ◽  
Wim De Waele ◽  
Patricia Verleysen ◽  
Nenad Gubeljak ◽  
Stijn Hertelé
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Tensile Testing ◽  
Industrial Process ◽  
Tensile Tests ◽  
Image Correlation ◽  
Heterogeneous Microstructure ◽  
Fusion Weld

Welding is a widely adopted industrial process used for joining components. A fusion weld has a highly heterogeneous microstructure and characterisation of strength heterogeneity is difficult because of the potentially large variations over a limited distance. Hardness mapping and miniature tensile tests are two distinct approaches to this problem. This paper reports on the possibilities and limitations of both techniques. Hardness mapping is a well-documented procedure as opposed to miniature tensile testing, where the dimensions of the dogbone shaped specimens are smaller than what standards prescribe. A particular challenge is the measurement of strains in such small specimens. The authors have achieved this measurement by means of Digital Image Correlation (DIC). To that end, a sufficiently fine speckling method has been developed.

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