scholarly journals Failure Mode Prediction of Resistance Spot Welded Quenching and Partitioning Steel

2019 ◽  
Vol 269 ◽  
pp. 03002 ◽  
Author(s):  
Cheng Luo ◽  
Yansong Zhang
Keyword(s):  
Tensile Strength ◽  
Failure Mode ◽  
Fusion Zone ◽  
Base Metal ◽  
Image Correlation ◽  
Constitutive Relationship ◽  
Quenching And Partitioning ◽  
Lap Shear ◽  
Relationship Of ◽  
Spot Welded

In recent years, a novel Advanced High-Strength Steels called quenching and partitioning (Q&P) steel has been applied in the automotive industry because its good combination of strength and ductility. In this study, an experimental setup by adopting digital image correlation (DIC) method was firstly developed to establish the constitutive relationship of fusion zone in the spot welds produced by Q&P980. Stress-strain relationship extracted from the tensile bar within the fusion zone and compared the results to that of base metal. The fusion zone of Q&P980 found to have a higher tensile strength and similar elongation compared with base metal. A numerical model established to predict the failure mode of joints generated by Q&P980 after obtaining the constitutive relationship of fusion zone. The predicted failure mode was in good coherence with the experimental results under the lap-shear test conditions. The developed FE model was proven efficient in tensile strength and failure mode characterization of spot welded specimen. This study could provide solutions to maintain or even improve vehicle crashworthiness of lightweight vehicle structures.

Investigate on Axial Load Behaviors of T-Shaped CFT Stub Columns with Binding Bars

2014 ◽  
Vol 501-504 ◽  
pp. 510-513
Author(s):  
Xin Zhi Zheng ◽  
Xin Hua Zheng
Keyword(s):  
Experimental Data ◽  
Bearing Capacity ◽  
Ultimate Strength ◽  
Failure Mode ◽  
Axial Compression ◽  
Axial Load ◽  
Constitutive Relationship ◽  
Relationship Of ◽  
Stub Columns

. Abstract. Tests on TCFT-WB, including 11 specimens with binding bars and 5 without binding bars under axial compression were carried out. The effects of parameters on the behavior of specimens such as failure mode, bearing capacity and ductility are analyzed to provide experimental data for the following research. The formula to calculate ultimate strength of TCFT-WB columns under axial compression are deduced from the constitutive relationship of TCFT-WB. The calculated results are compared with those calculated by FEM analyses, showing the proposed formula can give reasonable predictions on the ultimate strength of TCFT-WB stub columns under axial compression.

Temperature and Strain Rate Effects on Tensile Strength and Inelastic Constitutive Relationship of Sn-Pb Solders

2003 ◽  
Vol 125 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Haruo Nose ◽  
Masao Sakane ◽  
Yutaka Tsukada ◽  
Hideo Nishimura
Keyword(s):  
Tensile Strength ◽  
Yield Stress ◽  
Stress Amplitude ◽  
Young Modulus ◽  
Constitutive Relationship ◽  
Strain Rates ◽  
Strain Rate Effects ◽  
Tension Tests ◽  
Rate Effects ◽  
Relationship Of

This paper describes the tensile strength and inelastic constitutive relationship of six types of Sn-Pb solders. Static tension tests were carried using 5Sn-95Pb, 10Sn-90Pb, 40Sn-60Pb, 60Sn-40Pb, 63Sn-37Pb, and 62Sn-36Pb-2Ag solders at the strain rates of 0.001–10.0%/s between temperatures of 313 K and 398 K. Strain rates faster than 2.0%/s were needed to obtain the time-independent Young modulus and yield stress of the solders. Tensile strength increased with increasing strain rates up to 10%/s. Parametric equations for predicting tensile strength, Young’s modulus and yield stress of Sn-Pb solders were developed as a function of temperature and Sn content. Plastic and creep constitutive equations were also proposed as a function of temperature and Sn content. The stress amplitude predicted by these equations agreed with the experimental results within ±2 MPa.

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.

Bond Properties of Ceramic Concrete Reinforced by Bamboo Bar

2013 ◽  
Vol 477-478 ◽  
pp. 920-925 ◽  
Author(s):  
Jian Zhou ◽  
Hai Ning Liu ◽  
Su Ma ◽  
Jing Jing Li ◽  
He Tao Hou
Keyword(s):  
Bond Strength ◽  
Failure Mode ◽  
Shear Failure ◽  
Constitutive Relationship ◽  
Bond Properties ◽  
Concrete Material ◽  
Pull Out ◽  
Laminated Bamboo ◽  
Relationship Of ◽  
Type Bond

Bond properties of ceramic concrete reinforced by bamboo bar were investigated based on pull-out tests. The influences of strength grade of ceramic concrete, material type, bond length, side length and notch spacing of bamboo bar on the bond strength between the bamboo bars and ceramic concrete were studied. The results show that the bond failure mode of ceramic concrete reinforced by bamboo bar without notch is majorly pulling-out failure, however, ceramic concrete reinforced by restructured bamboo (RB) bar with notch appears shear failure mode. The ultimate bond strength of ceramic concrete reinforced by RB bars is higher than that of ceramic concrete reinforced by laminated bamboo (LB) bar, which is close to that of ceramic concrete reinforced by plastic bars,but lower than that of ceramic concrete reinforced by steel bars under the same condition. When the notch spacing is 15 mm, the bond strength of ceramic concrete reinforced by RB bars is the highest. The conclusions can be usable for the the constitutive relationship of ceramic bamboo-reinforced concrete.

scholarly journals Failure Study of Two Dissimilar Steels Joined by Spot Welding Technique

2018 ◽  
Vol 778 ◽  
pp. 262-267
Author(s):  
Ali Dad Chandio ◽  
Nabeel Ahmed Khan ◽  
Rameez Jawaid ◽  
Syed Naqi Mohsin
Keyword(s):  
Failure Mode ◽  
Fusion Zone ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Sheet Material ◽  
Weld Zone ◽  
Resistance Spot ◽  
Pull Out ◽  
Lap Shear ◽  
Dissimilar Alloys

Resistance spot welding (RSW) process is of paramount importance in automotive industry for the fabrication of metallic components. Several dissimilar alloys could easily be joined by resistance spot welding. However, the joining of the stainless steel and galvanized carbon steel is challenging task since weld fusion zone properties are affected significantly. Indeed, the reliability of the component lies in the sound quality of spot weld. The overload failure mode of the weld zone was determined by preparing lap-shear specimens and then carrying out tensile-shear test. Microstructures and hardness of the weld nuggets were also brought under considerations. It was found that weld nugget size and strength of that sheet material which has lower electrical resistance are the controlling factors of the failure mode. The aim of this study was to find out the causes of spot welds failure in terms of parameters favoring the pull-out failure mode, role of fusion zone size (FZS), nugget and base metal by controlling the process parameters.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

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