Design and fabrication of a metal-composite hybrid pantograph upper arm by co-cure technique with a friction layer

A pantograph is a part in trains that receives electricity by contacting with a contact wire. During driving conditions, de-wiring of the pantograph may occur owing to the movement of the train resulting in a temporary interruption of power supply and noise during re-contact. To solve this problem, it is necessary to make the pantograph lighter and stiffer, and therefore, fibrous composites are gaining attention to meet the needs for high performance pantographs. A parametric study is performed to determine the configurations of carbon/epoxy composite laminates with appropriate stiffness for a high-performance metal-composite hybrid pantograph. To avoid excessive thermal stress at the interface between the outer aluminum tube and inner composite tube, a friction layer made of a Teflon film is applied during the co-curing process. Finite element (FE) analysis is conducted to evaluate the structural integrity of the hybrid structures. Bending stiffness, natural frequencies with the corresponding modes, and the generated stresses owing to thermoforming are estimated according to the stacking sequence, and the most appropriate choice is determined. A prototype of the designed pantograph is fabricated, and the structural stiffness is estimated and compared with the FE analysis result, with which it shows good agreement.