A Control Method for the Ultrasonic Spot Welding of Fiber-Reinforced Thermoplastic Laminates through the Weld-Power Time Derivative
| Autor: | Martin Dannemann, Fabian Fischer, Shahan Tutunjian, Oguzhan Eroglu, Niels Modler |
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| Rok vydání: | 2018 |
| Předmět: |
0209 industrial biotechnology
Thermoplastic Materials science 02 engineering and technology Welding Temperature measurement ultrasonic welding Industrial and Manufacturing Engineering 020501 mining & metallurgy law.invention 020901 industrial engineering & automation fiber-reinforced thermoplastic laminates joining of fiber-reinforced thermoplastic composites law Composite material Spot welding Overheating (electricity) lcsh:T58.7-58.8 chemistry.chemical_classification Ultrasonic welding ultrasonic weld control system Mechanical Engineering differential ultrasonic spot welding 0205 materials engineering chemistry Mechanics of Materials Time derivative Ultrasonic sensor lcsh:Production capacity. Manufacturing capacity |
| Zdroj: | Journal of Manufacturing and Materials Processing Volume 3 Issue 1 Journal of Manufacturing and Materials Processing, Vol 3, Iss 1, p 1 (2018) |
| ISSN: | 2504-4494 |
| DOI: | 10.3390/jmmp3010001 |
| Popis: | It was found that the ultrasonic spot welding may serve as an efficient method to join relative large thin-walled parts made of fiber-reinforced thermoplastics. In this study, a new control method for the ultrasonic spot-welding process was investigated. It was found that, when welding fiber-reinforced thermoplastic laminates without energy directors, overheating and decomposition of the polymer at the weld spot occurred. The occurrence of the overheating took place at unpredictable times during welding. It was observed that the time trace of the consumed power curve by the welder follows a similar pattern as the time trace of the temperature in the weld spot center. Based on this observation, a control system was developed. The time derivative of the welder power was monitored in real time and, as soon as it exceeded a critical value, the ultrasonic vibration amplitude was actively adjusted through a microcontroller. The controlling of the ultrasonic welding process forced the temperature in the weld spot to remain in an adequate range throughout the welding duration for the polymer diffusion to occur. The results of the controlled welding process were evaluated by means of weld temperature measurements, computed tomography scans, and microscopic analysis of the weld spot fracture surfaces. |
| Databáze: | OpenAIRE |
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