A Novel Approach to Process Modeling for Ultrasonic Plastics Welding

2010 ◽  
Author(s):  
M. Ying ◽  
C. K. Cheng ◽  
J. Wei
Keyword(s):  
Process Parameters ◽  
Process Modeling ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Dissipated Energy ◽  
Measured Temperature ◽  
Novel Approach ◽  
Interfacial Temperature ◽  
Welding Pressure ◽  
Fully Coupled

Ultrasonic plastics welding is a widely employed joining technique for thermoplastic polymer assembly nowadays. As one fusion joining method, the ultrasonic welding quality is mainly dependent on the interfacial temperature which is affected by many process factors, such as welding time, welding pressure, and vibration amplitude, as well as material properties. Many attempts have been made to understand the mechanism of creation of an ultrasonic weld but limited by the complexity of the welding process. The current study developed a novel approach to process modeling for ultrasonic plastics welding. The thermoplastic materials were characterized with time domain viscoelastic model. The energy dissipation by the viscoelasticity was converted into the heating source which caused the temperature rose. The temperature change affected the material and structure responses and eventually the dissipated energy. As such, a fully coupled thermal-stress finite element (FE) model was established to simulate the performances of the ultrasonic welding. With the fully coupled model, the temperature distribution and displacement could be solved accurately and simultaneously. Meanwhile, the interfacial temperature was experimentally measured under the different process parameters. The simulation model was further validated by the measured temperature. With this novel approach, the ultrasonic plastics welding process can be completely simulated and the process parameters can be optimized numerically.

Features of the Heating Process in Ultrasonic Welding of Polycarbonate Products under Independent Pressure

2020 ◽  
pp. 54-62
Author(s):  
S.S. Volkov ◽  
A.L. Remizov ◽  
A.S. Pankratov
Keyword(s):  
Welded Joints ◽  
Welded Joint ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Heating Process ◽  
Mechanism Of Formation ◽  
High Quality ◽  
Acoustic Contact ◽  
Welding Pressure

This paper presents a mechanism of formation of a hard-to-weld polycarbonate joint by ultrasonic welding. The method utilizes internal and external friction occurring in the welded joint area on abutting surfaces due to shear vibrations of the end of the upper part relative to the lower part. A layer of the heated welded material is formed, localized by thickness, in which predominant absorption of the ultrasonic vibrations occurs, which allows one to obtain high-quality and durable welded joints without significant deformation due to the concentration of thermal energy in the welding zone. The effect of independent welding pressure on the strength of the welded joint of polycarbonate is considered. A new method of ultrasonic welding under the conditions of independent pressure is proposed. The method consists of dividing the static welding pressure into two components: the pressure of the acoustic contact in the zone of contact of the waveguide with the product, and the welding pressure that compresses the welded products, with the latter component being lower than the former. In order to obtain high-quality welded joints made of polycarbonate and to prevent displacement of the welded edges during the welding process relative to each other, a special preparation of the welded edges is developed, which allows one part to be moved vertically relative to the other during the welding process. It is established that the quality of welding depends on the speed of movement and the angle of cutting the edges.

Thermo Mechanical Analysis of Ultrasonic Welding of Metal Joints Under Different Control Parameters

2015 ◽  
Author(s):  
Dalong Yi ◽  
Hui Zhang ◽  
Lili Zheng
Keyword(s):  
Plastic Deformation ◽  
Process Parameters ◽  
Welding Process ◽  
Element Model ◽  
Mechanical Analysis ◽  
Ultrasonic Welding ◽  
Control Parameters ◽  
Bond Quality ◽  
Atom Diffusion ◽  
And Control

Ultrasonic welding is a complex process combining the processes of interface friction, heat transfer, plastic deformation heating, and atom diffusion and so on. Even though much work has been performed to understand ultrasonic welding process, the key characteristic process parameters of ultrasonic welding process and the key control parameters for the bond quality are still questions. Based on the interactions of bond factors and previous research of ultrasonic welding process, we believe that plastic deformation and temperature which represent the energy and strain condition at bonding interface are the key process parameters related to bond. A 3-D thermal-mechanical finite element model is built to analyze the thermal and mechanical files of ultrasonic welding process of two types of aluminum alloys under different control parameters. A possible mechanism between bond quality and control parameters based on max temperature and max plastic deformation of temperature-strain map of simulation is presented.

scholarly journals Molecular Dynamics Simulations of Atomic Diffusion during the Al–Cu Ultrasonic Welding Process

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2306 ◽  
Author(s):  
Jingwei Yang ◽  
Jie Zhang ◽  
Jian Qiao
Keyword(s):  
Molecular Dynamic ◽  
Weld Zone ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Atomic Scale ◽  
Atomic Diffusion ◽  
Dynamic Simulations ◽  
Diffusion Mechanisms ◽  
Interfacial Temperature ◽  
Dynamics Simulations

Ultrasonic welding (UW) is an important joining technique in the electrical industry. Molecular dynamic simulation has been shown to possess several advantages for revealing the evolution of the atomic-scale structure and the interpretation of diffusion mechanisms at the microscopic level. However, voids associated with the understanding of microstructure evolution in the weld zone and dynamic processes that occur during ultrasonically welded materials still exist, and no UW studies at the atomic scale have so far been reported. In this study, molecular dynamic simulations of UW between Al and Cu were performed to investigate the diffusion behaviors of Al and Cu atoms. The results confirmed the occurrence of asymmetrical diffusion at the Al/Cu interface during UW. Meanwhile, recovery was noticed in the disordered Al blocks at low temperature. The thickness of the diffusion layer increased with the welding time. For relatively long welding times (1 ns), the concentrations of Al and Cu revealed the appearance of phase transitions. In addition, the diffusion during UW was identified as a dynamic and unsteady process. The diffusion coefficient was much larger than that underwent during the steady diffusion process despite the low interfacial temperature (below 375 K), which was mainly attributed to shear plastic deformation at the interface.

Ultrasonic Welding of Glass Fiber Reinforced PP Thermoplastic Composites: An Investigation of the Outer Layer Orientation and the Fiber Volume Fraction

2020 ◽  
Vol 858 ◽  
pp. 3-13
Author(s):  
Murtada Abass A. Alrubaie
Keyword(s):  
Shear Strength ◽  
Glass Fiber ◽  
Outer Layer ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Fiber Volume ◽  
Energy Director ◽  
Welding Pressure

This paper presents an experimental study of the influence of the orientation of the outer layer of polypropeylene (PP) reinforced with E-glass fiber laminate (GF/PP) and the influence of the fiber volume fraction on the quality of the welded joint using an ultrasonic welding process. An orthogonal L 16 array (OA) design of experiment was conducted in this paper based on the Taguchi method to evaluate the effect of the orientation of the outer layer and the fiber volume fraction, on the welding process parameters; the welding energy, the amplitude of vibration, the welding pressure, the holding pressure and the holding time were considered in order to achieve a high weld quality. The experiments were carried out using a 15 kHz ultrasonic welding unit with a maximum supplied power of 4000-Watt. GF/PP laminates with fiber volume fraction of 36% and 46% were used in this paper, and the GF/PP laminates were either unidierctional or had a 90 degree outer layer orienation. A 0.127 mm thick polypropeylene film was used as a flat energy director (ED). The evaluation of the weld quality was measured by the apparent shear strength of the single lap welded joints, and by using laser shearography as a non-destructive inspection technique . The failure mechanism of the single lap joint was monitored, using a high speed digital imaging system. A combination of the highest selected level of welding energy, lowest level of amplitude, lowest level of welding pressure, and the lowest level of both hold time and hold pressure of a unidirectional GF/PP with the lowest fiber volume fraction, were found to achieve a higher apparent shear strength of the welded adherends, as compared with the apparent shear strength obtained with the presence of the flat energy director for the same level of factors. A confirmation experiment was conducted to measure the predicted apparent shear strength and compare it with the measured apparent shear strength from the test.

Effect of ultrasonic welding process parameters on hydrostatic pressure resistance of hybrid textiles for weather protection

2021 ◽  
pp. 004051752098812
Author(s):  
Muktar Seid Hussen ◽  
Yordan Kostadinov Kyosev ◽  
Kathrin Pietsch ◽  
Stefan Rothe ◽  
Abera Kechi
Keyword(s):  
Hydrostatic Pressure ◽  
Process Parameters ◽  
Welding Process ◽  
Preliminary Test ◽  
Ultrasonic Welding ◽  
Welding Parameters ◽  
Hot Air ◽  
Pressure Resistance ◽  
Different Levels

In the research project presented in this paper, the effects of welding width, pressure force, power, and speed of ultrasonic welding parameters on hydrostatic pressure resistance were examined. A flexible and lightweight PVC-coated hybrid textile material with uniform thickness was used for weather protection purposes. Three main welding parameters at three different levels were selected based on the preliminary test results involving welding widths of 6 and 12 mm. A lapped type of seam was applied for ultrasonic welding and conventional joining techniques. A conventionally sewn zigzag seam was produced using three main factors at two different levels according to the application area. To avoid seam permeability, the conventional seam was sealed with tape by means of hot-air tape welding and subsequently investigated regarding its hydrostatic pressure resistance. The hydrostatic pressure resistance value of the conventional seam was then compared with ultrasonic weld seams of 6 and 12 mm welding width, and its parametric influence on the quality of the seam was analyzed. The result shows that the ultrasonic weld seam with a 12 mm welding width provided a higher hydrostatic pressure resistance than the 6 mm welding width and the conventionally sewn seam. Statistical analyses were also carried out to prove the significant effect of welding process parameters on hydrostatic pressure resistance, whereby the obtained results were statistically significant. A suitable nonlinear numerical model was also developed to predict the hydrostatic pressure resistance.

scholarly journals Ultrafast Parallel Micro-Gap Resistance Welding of an AuNi9 Microwire and Au Microlayer

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
He Zhang ◽  
Shang Wang ◽  
Bingying Wu ◽  
Weiwei Zhang ◽  
Chunjin Hang ◽  
...  
Keyword(s):  
Melting Point ◽  
Process Parameters ◽  
Electrical Contact ◽  
Welding Process ◽  
Welding Current ◽  
Resistance Welding ◽  
Dynamic Resistance ◽  
Welding Time ◽  
Welding Temperature ◽  
Welding Pressure

Welding between an AuNi9 microwire and Au microlayer is of great importance for fabricating electrical contact structures for high precision inertial devices, satellite slip ring brushes, robots, etc. In this paper, the achievement of parallel micro-gap resistance welding (PMRW) with 200-μm AuNi9 microwires on a 3-μm Au layer was presented. The study on the orthogonal design of the experiment was carried out. The effect of the process parameters (welding current, welding time, and welding pressure) was discussed in reference to the morphologies and tensile force of the joint using range analysis. It is shown that too much or too little heat input will decrease the welding performance. A group of optimized process parameters (0.275 kA welding current, 3 ms welding time, and 28.7 N welding pressure) was obtained. During the welding process, the dynamic resistance of the whole welding system was measured, which can reflect the welding quality. Finite element simulation is utilized to calculate the welding temperature. The highest temperature was located in the center area of the AuNi9 microwire, reaching 1397.2 °C, which is higher than the melting point of AuNi9. By contrast, the highest temperature for the pad was 826.47 °C (lower than the melting point of Au). Hence, under optimized process parameters, a transient interfacial reaction between the liquid AuNi9 microwire and solid Au pad occurred, and the strength of the welded joint reached 5.54 N.

Efficiency of the Inertia Friction Welding Process and Its Dependence on Process Parameters

2017 ◽  
Vol 48 (7) ◽  
pp. 3328-3342 ◽  
Author(s):  
O. N. Senkov ◽  
D. W. Mahaffey ◽  
D. J. Tung ◽  
W. Zhang ◽  
S. L. Semiatin
Keyword(s):  
Process Parameters ◽  
Friction Welding ◽  
Welding Process ◽  
Inertia Friction Welding

Ultrasonic Torsion Welding of Aging Resistant Al/CFRP Joints - Concepts, Mechanical and Microstructural Properties

2017 ◽  
Vol 742 ◽  
pp. 395-400 ◽  
Author(s):  
Florian Staab ◽  
Frank Balle ◽  
Johannes Born
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Materials Science ◽  
Dissimilar Materials ◽  
Material Design ◽  
Ultrasonic Welding ◽  
Fatigue Properties ◽  
Aviation Industry ◽  
Efficient Design ◽  
Engineering Structures

Multi-material-design offers high potential for weight saving and optimization of engineering structures but inherits challenges as well, especially robust joining methods and long-term properties of hybrid structures. The application of joining techniques like ultrasonic welding allows a very efficient design of multi-material-components to enable further use of material specific advantages and are superior concerning mechanical properties.The Institute of Materials Science and Engineering of the University of Kaiserslautern (WKK) has a long-time experience on ultrasonic welding of dissimilar materials, for example different kinds of CFRP, light metals, steels or even glasses and ceramics. The mechanical properties are mostly optimized by using ideal process parameters, determined through statistical test planning methods.This gained knowledge is now to be transferred to application in aviation industry in cooperation with CTC GmbH and Airbus Operations GmbH. Therefore aircraft-related materials are joined by ultrasonic welding. The applied process parameters are recorded and analyzed in detail to be interlinked with the resulting mechanical properties of the hybrid joints. Aircraft derived multi-material demonstrators will be designed, manufactured and characterized with respect to their monotonic and fatigue properties as well as their resistance to aging.

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