Investigation of GFRP/AA7075-T6 Scarf Joint as a Robot Arm for High Natural Frequency and Damping Ratio

Gençer G. M., Öztoprak N., Akdağ M., Şen H.

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING, vol.49, pp.2027-2044, 2024 (SCI-Expanded)

  • Publication Type: Article / Article
  • Volume: 49
  • Publication Date: 2024
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Aerospace Database, Communication Abstracts, Metadex, Pollution Abstracts, zbMATH, Civil Engineering Abstracts
  • Page Numbers: pp.2027-2044
  • Dokuz Eylül University Affiliated: Yes


One of the most important factors negatively affecting the efficiency of a robot arm is excessive weight. Therefore, the present work is focused on the application of polymer-metal composite instead of monolithic aluminum (Al) beam for high free vibration performance with lightweight. Vibration behavior of the robot arm with a scarf joint configuration is evaluated through the experimental and simulation results. Moreover, mechanical properties and interface morphology of the hybrid beam (HB) are investigated. Scanning electron microscope (SEM) analysis of the fracture surfaces is also performed after the tensile-shear testing. According to the experimental results, it is observed that the natural frequency and damping ratio are improved for the HB compared to the monolithic aluminum by 21.36% and 150%, respectively. Furthermore, the obtained simulation results are in tight agreement with the experimental findings. After the parametric study performed, it is discovered that the ratio of aluminum component in the hybrid robot arm should be 70.45% for the maximum frequency. The physicochemical variation on the metallic adherend after the laser ablation and accordingly the formation of more favorable conditions is proved for the Al-PA66 composite direct bonding. An average failure load of 2844 N is achieved, and it has been realized that the post-tensile fractured surfaces demonstrate a combined failure mode as the cohesive with composite adherend failure. The overall results show that a higher natural frequency and damping ratio, accompanied by favorable mechanical properties, can be achieved for the HB produced through direct bonding in the scarf configuration.