Investigation of the usability of composite materials in hydraulic cylinders

In this study, it was aimed to use composite materials, which stand out with their high strength/weight ratio, instead of conventional steels to reduce hydraulic cylinders weight. In this context, two different hydraulic cylinders designated as Type 1 and Type 2 were designed, and numerical analyses were conducted with the ANSYS package program. For the Type 1 hydraulic cylinders, an aluminum liner with geodesic dome profiles was used, and composite layers were formed on its surface. Likewise, the open-ended aluminum liner was used for the Type 2 hydraulic cylinders and composite layers were formed on its surface. In the numerical analyses, the effects of the design parameters such as polar opening radii, liner thickness, stacking sequences, fiber materials, hoop winding utilization and fiber orientations on the mechanical properties were investigated. Furthermore, the design parameters were optimized by virtue of response surface optimization, and thus the optimum design parameters were determined for both hydraulic cylinders. As a result of the current study, it has been concluded that the increment in the polar opening radii had significant improvement effects on the helical winding angles and hence on the mechanical properties. Moreover, it has been revealed that the helical winding layers may be insufficient against axial loads and therefore, hoop winding layers should be used as reinforcement layers to withstand tangential loads. Apart from that, it has been determined that composite hydraulic cylinders with the same strength as steel hydraulic cylinders can be designed. Additionally, with the utilization of the composite materials, it has been observed that Type 1 and Type 2 hydraulic cylinders are 53.78% and 38.42% lighter than conventional hydraulic cylinders, respectively.