This paper investigates the manufacturing variants influential on the strength of 3D printed products. In contrast to the traditional manufacturing methods which produce the final product via removing materials from parts, in 3D printing technology the products are provided with adding layer by layer directly from a digital file. 3D printing technology due to overcoming the many difficulties and limitations of conventional fabrication approaches is a rapidly progressing technology which takes attention in many industries such as aerospace, automotive, medical and building industries. This paper aims to research the variants affecting the mechanical properties of components produced by 3D printing technologies. To reach this aim a comprehensive review was conducted to determine the various process and geometric parameters in 3D printing technologies. The conducted literature survey results indicate that besides the filament material, the nozzle speed and diameter, layer thickness, filament diameter, printing raster angle, printing pattern, temperature and infill density are parameters which influence the final product quality and mechanical properties in term of ultimate tensile strength, yield stress and elasticity modulus. It is concluded that 3D printing filament materials strength has direct affect on the strength of final product. By providing the adequate thermal behavior of the system, the cohesion between layers can be improved. Extrusion speed affects surface roughness and quality of the produced components. Nozzle diameter has a significant influence on interlayer cohesion. The honeycomb pattern due to facilitating the load transfer between layers provides higher mechanical strength. Findings of this study will guide the researchers and manufacturers to select appropriate printing parameters to produce component with optimum mechanical properties.

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In this study, mass minimization of a simple double-acting hydraulic cylinder has been studied using The Bees Algorithm (BA) for a specific force and known material, considering the buckling and pressure constraints. A Hydraulic cylinder is a hydraulic actuator that creates linear movement by converting hydraulic energy back to a mechanical movement. Hydraulic-driven working machines are widespread in the industry today. Hydraulic cylinders are used in mobile applications such as container lifting devices, excavators, dump trucks, loaders, graders and dozers. Weight reduction in these cylinders plays a fundamental role in the performance of the machine in terms of lifting capacity, speed, costing, etc. The Bees Algorithm is a metaheuristic algorithm that mimics the natural foraging behavior of honey bees to find the optimum solutions. The advantages over other algorithms are its ability to search both locally and globally and being applicable for several optimization problems with the chance to be integrated with other algorithms. In this study, it is also aimed to determine the optimal parameters of the bees algorithm for minimum computation cost.