Numerical Study on Stress Distribution in Ultrasonically Welded Electrical Contacts used in Automotives

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
J. Pradeep Kumar ◽  
M.S. Arun Kumar ◽  
N. Gowsalya Devi ◽  
M. Naveen Kumar ◽  
S.M. Pavith Raja
Keyword(s):  
Numerical Study ◽  
Theoretical Calculations ◽  
Copper Wire ◽  
Electrical Contact ◽  
Welding Process ◽  
Electrical Contacts ◽  
Copper Sheet ◽  
Element Analysis ◽  
Ultrasonic Metal Welding ◽  
Metal Welding

Numerical stress analysis while joining an electrical contact comprising of copper wire and copper sheet using ultrasonic metal welding process is vital in many of the automotive applications. During ultrasonic metal welding, shear and normal force act at the interface between the welded specimens. These forces are the result of ultrasonic vibrations transmitted by Sonotrode onto the welded specimens. In this work, the distribution of the stress developed at the interface and the correlation of the developed stress with strength of joint are studied. The theoretical stress values are determined using various levels of ultrasonic metal welding process parameters such as clamping force, vibration amplitude and weld time to validate the results of stress obtained from finite element analysis. The results of stress from numerical analysis are found to be in good agreement with that of results obtained from the theoretical calculations.

Process Monitoring in Ultrasonic Metal Welding of Lithium Batteries by Power Signals

2021 ◽  
pp. 1-22
Author(s):  
Xinhua Shi ◽  
Lin Li ◽  
Suiran Yu ◽  
Lingxiang Yun
Keyword(s):  
Electric Power ◽  
Process Monitoring ◽  
Lithium Batteries ◽  
Welding Process ◽  
Ultrasonic Metal Welding ◽  
Isometric Transformation ◽  
Welding Defects ◽  
Different Types ◽  
Metal Welding ◽  
Welding Processes

Abstract Ultrasonic metal welding is one of the key technologies in manufacturing lithium batteries, and the welding quality directly determines the battery performance. Therefore, an online welding process monitoring system is critical in identifying abnormal welding processes, detecting defects, and improving battery quality. Traditionally, the peak welding power is used to indicate abnormal process signals in welding process monitoring systems. However, since various factors have complex impacts on the electric power signals of ultrasonic welding processes, the peak power is inadequate to detect different types of welding defects. Therefore, a signal pattern matching method is proposed in this study, which is based on the electric power signal during the entire welding process and thus is capable of identifying abnormal welding processes in various conditions. The proposed method adopts isometric transformation and homogenization as signal pretreatment methods, and Euclidean distance is used to calculate the similarity metric for signal matching. The effectiveness and robustness of the proposed method are experimentally validated under different abnormal welding conditions.

Ultrasonic Rapid Manufacturing: Implementation and Thermo-Mechanical Analysis

2002 ◽  
Author(s):  
Shailendra Yadav ◽  
Charalabos Doumanidis
Keyword(s):  
Temperature Effects ◽  
Welding Process ◽  
Mechanical Analysis ◽  
Ultrasonic Welding ◽  
Solid Metal ◽  
Rapid Manufacturing ◽  
Mechanical Process ◽  
Ultrasonic Metal Welding ◽  
Metal Parts ◽  
Metal Welding

This paper addresses a novel non-thermal Ultrasonic Rapid Manufacturing (URM), for layered parts based on Ultrasonic Metal Welding (USW). Its laboratory implementation, automation and integration are described first. The thermo-mechanical process aspects (i.e. heat generation and resulting temperature effects) during each cycle of ultrasonic welding are then studied. The technical advantages of ultrasonic welding process, including fabrication of dense, full-strength functional solid metal parts, multi-material composites, and active parts with embedded intelligent components and electronic, mechatronic, optic and fluidic structures, are examined.

Numerical Study of Welding with Trailing Heat Sink Considering Phase Transformation Effects

2014 ◽  
Vol 875-877 ◽  
pp. 2118-2122
Author(s):  
Shirish R. Kala ◽  
N. Siva Prasad ◽  
G. Phanikumar
Keyword(s):  
Finite Element ◽  
Phase Transformation ◽  
Residual Stresses ◽  
Material Properties ◽  
Heat Sink ◽  
Numerical Study ◽  
Gaussian Model ◽  
Welding Process ◽  
Source Model ◽  
Element Analysis

Welding process with trailing heat sink for 2 mm mild steel plates has been analyzed to estimate distortion and residual stresses using a finite element modeling software Sysweld. The material properties used for the analysis are both temperature dependent and phase dependent. A transient thermal analysis is carried out using Goldak double ellipsoidal heat source model and heat sink as Gaussian model with negative heat flux. The finite element analysis (FEA) is conducted by considering the material properties of all phases of steel as well as without phase transformation i.e. by considering properties of only ferrite phase. Temperature distribution, distortion and residual stresses are calculated and compared for four cases: without phase without cooling, without phase with cooling, with phase without cooling and with phase with cooling. It is found that FEA without phase transformation effects overestimates the residual stresses in the fusion zone (FZ) and heat affected zone (HAZ). It is also found that a trailing heat sink reduces transverse compressive residual stresses thus minimizing the possibilities of buckling.

Dynamics of Battery Tabs Under Ultrasonic Welding

2013 ◽  
Author(s):  
Bongsu Kang ◽  
Wayne Cai ◽  
Chin-An Tan
Keyword(s):  
Longitudinal Vibration ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Point Of View ◽  
Structural Vibration ◽  
Kinetic Properties ◽  
Weld Quality ◽  
Ultrasonic Metal Welding ◽  
Metal Welding ◽  
Welding Processes

Ultrasonic metal welding for battery tabs must be performed with 100% reliability in battery pack manufacturing as the failure of a single weld essentially results in a battery that is inoperative or cannot deliver the required power due to the electrical short caused by the failed weld. In ultrasonic metal welding processes, high-frequency ultrasonic energy is used to generate an oscillating shear force (sonotrode force) at the interface between a sonotrode and few metal sheets to produce solid-state bonds between the sheets clamped under a normal force. These forces, which influence the power needed to produce the weld and the weld quality, strongly depend on the mechanical and structural properties of the weld parts and fixtures in addition to various welding process parameters such as weld frequencies and amplitudes. In this work, the effect of structural vibration of the battery tab on the required sonotrode force during ultrasonic welding is studied by applying a longitudinal vibration model for the battery tab. It is found that the sonotrode force is greatly influenced by the kinetic properties, quantified by the equivalent mass and equivalent stiffness, of the battery tab and cell pouch interface. This study provides a fundamental understanding of battery tab dynamics during ultrasonic welding and its effects on weld quality, and thus provides useful guidelines for design and welding of battery tabs from tab dynamics point of view.

Characterization of Ultrasonic Metal Welding by Correlating Online Sensor Signals With Weld Attributes

2014 ◽  
Author(s):  
S. Shawn Lee ◽  
Chenhui Shao ◽  
Tae Hyung Kim ◽  
S. Jack Hu ◽  
Elijah Kannatey-Asibu ◽  
...  
Keyword(s):  
Welding Process ◽  
Deep Understanding ◽  
Lithium Ion ◽  
Ultrasonic Welding ◽  
Diagnostic Methods ◽  
Quality Monitoring ◽  
Process Conditions ◽  
Ultrasonic Metal Welding ◽  
Bond Density ◽  
Metal Welding

Online process monitoring in ultrasonic welding of automotive lithium-ion batteries is essential for robust and reliable battery pack assembly. Effective quality monitoring algorithms have been developed to identify out of control parts by applying purely statistical classification methods. However, such methods do not provide the deep physical understanding of the manufacturing process that is necessary to provide diagnostic capability when the process is out of control. The purpose of this study is to determine the physical correlation between ultrasonic welding signal features and the ultrasonic welding process conditions and ultimately joint performance. A deep understanding in these relationships will enable a significant reduction in production launch time and cost, improve process design for ultrasonic welding, and reduce operational downtime through advanced diagnostic methods. In this study, the fundamental physics behind the ultrasonic welding process is investigated using two process signals, weld power and horn displacement. Several online features are identified by examining those signals and their variations under abnormal process conditions. The joint quality is predicted by correlating such online features to weld attributes such as bond density and post-weld thickness that directly impact the weld performance. This study provides a guideline for feature selection and advanced diagnostics to achieve a reliable online quality monitoring system in ultrasonic metal welding.

Characterization of Ultrasonic Metal Welding by Correlating Online Sensor Signals With Weld Attributes

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
S. Shawn Lee ◽  
Chenhui Shao ◽  
Tae Hyung Kim ◽  
S. Jack Hu ◽  
Elijah Kannatey-Asibu ◽  
...  
Keyword(s):  
Welding Process ◽  
Deep Understanding ◽  
Lithium Ion ◽  
Ultrasonic Welding ◽  
Diagnostic Methods ◽  
Quality Monitoring ◽  
Process Conditions ◽  
Ultrasonic Metal Welding ◽  
Bond Density ◽  
Metal Welding

Online process monitoring in ultrasonic welding of automotive lithium-ion batteries is essential for robust and reliable battery pack assembly. Effective quality monitoring algorithms have been developed to identify out of control parts by applying purely statistical classification methods. However, such methods do not provide the deep physical understanding of the manufacturing process that is necessary to provide diagnostic capability when the process is out of control. The purpose of this study is to determine the physical correlation between ultrasonic welding signal features and the ultrasonic welding process conditions and ultimately joint performance. A deep understanding in these relationships will enable a significant reduction in production launch time and cost, improve process design for ultrasonic welding, and reduce operational downtime through advanced diagnostic methods. In this study, the fundamental physics behind the ultrasonic welding process is investigated using two process signals, weld power and horn displacement. Several online features are identified by examining those signals and their variations under abnormal process conditions. The joint quality is predicted by correlating such online features to weld attributes such as bond density and postweld thickness that directly impact the weld performance. This study provides a guideline for feature selection and advanced diagnostics to achieve a reliable online quality monitoring system in ultrasonic metal welding.

Microstructural and Joint Analysis of Ultrasonic Welded Aluminum to Cupro-Nickel Sheets for Lithium-Ion Battery Packs

2020 ◽  
Vol 978 ◽  
pp. 463-469
Author(s):  
Soumyajit Das ◽  
Mantra Prasad Satpathy ◽  
Bharat Chandra Routara ◽  
Susanta Kumar Sahoo
Keyword(s):  
Bond Strength ◽  
Lithium Ion Battery ◽  
Welding Process ◽  
Lithium Ion ◽  
Joint Analysis ◽  
Shop Floor ◽  
Ultrasonic Frequency ◽  
Ultrasonic Metal Welding ◽  
Battery Packs ◽  
Metal Welding

Energy crisis poses a major challenge in the modern industrial scenario. A critical aspect of the shop floor work includes the welding of dissimilar metal sheets which require the right amount of energy. In order to tackle these challenges, a conservative and energy efficient method are necessary. Recently, automotive industries have been widely adopted the ultrasonic metal welding process for assembling lithium-ion battery packs and its modules. The joining of these dissimilar metals using any other conventional welding process is extremely challenging due to varying physical, chemical, thermal properties, the formation of the heat affected zone and lesser bond strength. However, ultrasonic metal welding yields better quality welds under the influence of optimal parametric conditions. In this research, the weld quality of two dissimilar materials, namely, aluminum (AA1060) with cupronickel (C71500) sheets investigated at different welding time, vibration amplitudes and welding pressures with a fixed ultrasonic frequency of 20 kHz. Experimental results show the tensile shear strength of the weld is maximum at the highest vibration amplitude with a moderate amount of weld pressure and weld time. Additionally, the joint quality and its associated microstructure at the weld region are analyzed by scanning electron microscopy (SEM) to reveal the bond strength with the interlocking feature.

Characterization of Ultrasonic Metal Welding Process

2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Sandra Matos ◽  
Fernando Veloso ◽  
Carlos Santos ◽  
Leonardo Gonçalves ◽  
Emanuel Carvalho
Keyword(s):  
Welding Process ◽  
Ultrasonic Metal Welding ◽  
Metal Welding
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