scholarly journals Correlation between Peel Test and Real Time Ultrasonic Test for Quality Diagnosis in Resistance Spot Welding

2016 ◽  
Vol 21 (3) ◽  
pp. 282-289 ◽  
Author(s):  
Angelo F. Andreoli ◽  
Andriy M. Chertov ◽  
Roman Gr. Maev
Keyword(s):  
Nondestructive Evaluation ◽  
Real Time ◽  
Spot Welding ◽  
Peel Test ◽  
Ultrasonic Test ◽  
Welding Time ◽  
Test Results ◽  
Industrial Environment ◽  
Quality Diagnosis ◽  
Potential Use

Abstract: This paper aimed to study the correlation between Real Time Integrated Weld Analyzer measurements and peel test results. The experiment involved study of weld nuggets for different combinations of sheet thicknesses, welding time and current of mild steel samples. The intent was to assess the potential use of a real time integrated ultrasonic system in the industrial environment allowing nondestructive evaluation of 100% of the spot welds produced. The results showed high correlation between nugget penetration into the sheets and nugget size measured ultrasonically and destructively, for all evaluated parameters.

scholarly journals Optimization of Spot Welding for Peel load on SPCC Steel Sheets

2020 ◽  
Vol 5 (1) ◽  
pp. 53
Author(s):  
Raden Edy Purwanto ◽  
Moh. Hartono ◽  
Yuniarto Agus Widodo
Keyword(s):  
Shear Strength ◽  
Time Variation ◽  
Null Hypothesis ◽  
Spot Welding ◽  
Plate Thickness ◽  
Testing Machine ◽  
Peel Test ◽  
Peel Strength ◽  
Work Piece ◽  
Welding Time

Spot welding is a process of connecting two metal components through one or more connection points by using heat from electrical resistance which is carried by two electrodes to the metal to be connected with a certain welding time. The purpose of this study is to determine the effect of voltage and time of pressure used for spot welding on the shear strength and peel strength on the SPCC plate. The variables used in this study are independent variables of electric current variation of 2.30 V, 2.70 V, 3.20 V and time variation of 3 seconds, 4 seconds, and 5 seconds with 1mm plate thickness. The dependent variable in this study is the calculation of shear strength and peel strength in universal testing machine, and the controlled variable in this study is 1mm plate thickness characteristic of SPCC palate work piece. The research method was carried out using the ANOVA Factorial with the null hypothesis that there was no influence of the spot welding time and voltage on spot welding on the shear strength and strength of the SPCC material's peel. The results of the study are for the shear test seen from the calculation using MINITAB, the time variation of the pressure is no effect, while for the voltage and the combination of time suppression and voltage there is influence. For strength testing, the null hypothesis is rejected for all variations, which means that there is an influence on the strength of the peel test.

Methodology to Increase Flexibility in Inter-Region Flow Control for Urban Traffic

2021 ◽  
pp. 036119812199742
Author(s):  
Sunghoon Kim ◽  
Monica Menendez ◽  
Hwasoo Yeo
Keyword(s):  
Flow Control ◽  
Real Time ◽  
Urban Traffic ◽  
Test Results ◽  
Flow Restriction ◽  
Region Flow ◽  
The Subject ◽  
Negative Impacts ◽  
Transfer Flow ◽  
Supply Level

Perimeter control is used to regulate transfer flows between urban regions. The greedy control (GC) method takes either the minimum or the maximum for the control inputs. Although it has the advantage of simplicity for real-time feasibility, a few existing studies have shown that it can sometimes have negative impacts because of unnecessary transfer flow restrictions. To reduce unnecessary restrictions, this study provides a method that gives flexibility to ease the strict conditions of the conventional GC. First, we propose a modification as a way of granting exceptions to the flow restriction under specific conditions. Second, we develop an algorithm to determine the threshold dynamically for accepting the exception, by comparing the possible outflow loss of the subject region and the possible outflow gain of its neighboring regions. The test results show that this flexible greedy control can handle the balance between the transfer demands and the greed of regions for securing the supply level, while increasing the performance in both vehicle hours traveled and trip completion.

scholarly journals Preanalytical Issues and Cycle Threshold Values in SARS-CoV-2 Real-Time RT-PCR Testing: Should Test Results Include These?

ACS Omega ◽  
2021 ◽  
Author(s):  
Ilka Engelmann ◽  
Enagnon Kazali Alidjinou ◽  
Judith Ogiez ◽  
Quentin Pagneux ◽  
Sana Miloudi ◽  
...  
Keyword(s):  
Real Time ◽  
Test Results ◽  
Threshold Values ◽  
Rt Pcr ◽  
Cycle Threshold

scholarly journals Hopkinson rod test results and constitutive description of TRIP780 steel resistance spot welding material

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 961-967
Author(s):  
Xiaomin Li ◽  
Jianrong Zhang
Keyword(s):  
Spot Welding ◽  
Steel Strip ◽  
Strain Curve ◽  
Test Machine ◽  
Strain Rates ◽  
Test Results ◽  
Welding Material ◽  
Static Tensile ◽  
Split Hopkinson ◽  
Brittle Fractures

Abstract A quasi-static tensile test was performed on a 1.4 mm-thick TRIP780 steel strip with welding points. An MTS810 material test machine was used in the test, and a Split Hopkinson tension bar device was used in performing impact stretch loading at different strain rates. The dynamic tensile stress–strain curve of the spot welding material with different strain rates was obtained through the finely designed Hopkinson rod test, and the strain rate dependence of a TRIP780 steel spot welding material was discussed. According to the dynamic constitutive equation of the TRIP780 steel spot welding material, the test results were numerically simulated, the constitutive description and test curves were compared, and the simulation results and test results were discussed and analyzed. The fractures of the test recovery specimen were scanned with the scanning electron microscope, and the fracture mechanism of the TRIP780 steel spot welding material was explored by observing the fractures. The surfaces of the fractures surface showed obvious cleavage river patterns, and the evolution process of microcracks was determined and used in characterizing brittle fractures in specimen spot welding sample subjected to dynamic stretch loading.

scholarly journals An Index of Regional Snow-Pack Stability based on Natural Slab Avalanches

1985 ◽  
Vol 31 (108) ◽  
pp. 67-73
Author(s):  
Arthur Judson ◽  
Rudy M. King
Keyword(s):  
Real Time ◽  
Testing Procedure ◽  
Statistical Distribution ◽  
Colorado Front Range ◽  
Sequential Testing ◽  
Test Results ◽  
Snow Pack ◽  
Front Range ◽  
Time Evaluation

AbstractAn index of regional snow-pack stability based on occurrences of natural slab avalanches was developed using a statistical distribution and a sequential testing procedure. The study interprets avalanche information on 185 paths in the Colorado Front Range. Results show general agreement with operational hazard estimates; test results have real-time evaluation potential.

scholarly journals Oxygen Monitoring Equipment for Sewage-Sludge Composting and Its Application to Aeration Optimization

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4017
Author(s):  
Guodi Zheng ◽  
Yuewei Wang ◽  
Xiankai Wang ◽  
Junxing Yang ◽  
Tongbin Chen
Keyword(s):  
Real Time ◽  
Oxygen Concentration ◽  
Consumption Rate ◽  
Continuous Control ◽  
Test Results ◽  
Monitoring Equipment ◽  
Decomposition Of Organic Matter ◽  
Good Repeatability ◽  
Oxygen Monitoring ◽  
Time Required

Oxygen is an important parameter for organic-waste composting, and continuous control of the oxygen in a composting pile may be beneficial. The oxygen consumption rate can be used to measure the degree of biological oxidation and decomposition of organic matter. However, without having a real-time online device to monitor oxygen levels in the composting pile, the adjustment and optimization of the composting process cannot be directly implemented. In the present study, we researched and developed such a system, and then tested its stability, reliability, and characteristics. The test results showed that the equipment was accurate and stable, and produced good responses with good repeatability. The equilibrium time required to detect oxygen concentration in the composting pile was 50 s, and the response time for oxygen detection was less than 2 s. The equipment could monitor oxygen concentration online and in real time to optimize the aeration strategy for the compost depending on the concentration indicated by the oxygen-measuring equipment.

scholarly journals Ultrasonic Spot Welding of Similar and Dissimilar Alloys for Automotive Applications

2021 ◽  
Author(s):  
Andrew Macwan
Keyword(s):  
Diffusion Layer ◽  
Spot Welding ◽  
Frictional Heating ◽  
Hsla Steel ◽  
Weight Ratio ◽  
High Strength ◽  
Phase Identification ◽  
Welding Time ◽  
Interface Diffusion ◽  
Lap Shear

Lightweighting has been regarded as a key strategy in the automotive industry to improve fuel efficiency and reduce anthropogenic environment-damaging, climate-changing, and costly emissions. Magnesium (Mg) alloys and Aluminum (Al) alloys are progressively more used in the transportation industries to reduce the weight of vehicles due to their high strength-to-weight ratio. Similarly, high strength low alloy (HSLA) steel is widely used to reduce gauge thickness and still maintain the same strength, and thereby reduce vehicle weight as well. A multi-material design of automotive structures and parts inevitably involve similar Mg-to-Mg and dissimilar Mg-to-Al, Al-to-steel, and Mg-to-Cu joints. Ultrasonic spot welding (USW) – a solid-state joining technique has recently received significant attention due to its higher efficiency in comparison with conventional fusion welding techniques. In this study, USW was used to generate similar joints of low rare-earth containing ZEK100 Mg alloy sheets and dissimilar ZEK100-to-Al5754, Al6111-to-HSLA steel, and Mg-to-Cu joints at different levels of welding energy or welding time. To optimize welding process and identify key factors affecting the weld strength, microstructural evolution, microhardness test, tensile lap shear test, fatigue test, and fracture analysis were performed on similar and dissimilar ultrasonic spot welded (USWed) joints. Dynamic recrystallization and grain coarsening were observed during Mg-to-Mg similar welding while rapid formation and growth of interface diffusion layer were observed in all dissimilar joints in the present study. It was due to significantly high strain rate (~103 s-1) and high temperature generated via frictional heating during USW. The interface diffusion layer was analyzed by SEM, EDS and XRD phase identification techniques which showed the presence of eutectic structure containing intermetallic compounds (IMCs). As a result, brittleness at the interface increased. The Zn coating in dissimilar USWed Al-to-steel joints eliminated the formation of brittle IMCs of Al-F, which were replaced by relatively ductile AlZn eutectic. The optimum welding energy or welding time during similar and dissimilar USW of lightweight alloys with a sheet thickness of 1-2 mm was in the range of ~500 J to 2000 J (~0.25 s to 1 s).

scholarly journals Real-time Measuring and Monitoring of Relevant Parameters in Complex Chain Conveyor Systems

2020 ◽  
Vol 1 ◽  
pp. 64-73
Author(s):  
Jens Strobel ◽  
Jens Sumpf ◽  
Ralf Bartsch ◽  
Markus Golder
Keyword(s):  
Real Time ◽  
Mechanical Characteristics ◽  
Test Results ◽  
Movement Behaviour ◽  
Conveyor System ◽  
Dynamic Movement ◽  
Potential Applications ◽  
Complete Failure ◽  
Chain Conveyor ◽  
Chain Links

In continuous conveyor systems with circulating traction mechanisms, e.g. chains, the kinematic-dynamic movement behaviour of the traction mechanism is of great importance. Force and vibration analyses can be used to detect overloads and other irregularities in the conveying process. This helps to prevent damage that can lead to a complete failure of the conveyor system. Such analyses are particularly interesting for slide chain conveyors with plastic chains, as these react very sensitively to system overload due to limited thermal and mechanical characteristics as well as often a complex track layout. This article shows how accelerations and tractive forces can be continuously recorded, transmitted and analysed by sensors integrated into the chain links. In addition to the discussion of test results, potential applications of the measuring chain are shown.

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