Nowadays Additive Manufacturing (AM) is going through a very fast development, spreading in many different mechanical contexts. The main advantages of this technology are: production costs reduction (prototype realization time reduction, raw material consumption reduction, almost zero manpower needed...), significant reliability (compared to the standard production process) and last but not least extreme freedom in product shape design. The last characteristic makes it possible to adopt new design approach focusing on component shape and material distribution optimization; a new design paradigm must be developed to fully take advantage of these opportunities: the designer can develop new concepts with very complex shapes and sophisticated topological solution owing to opportunities yielded by AM with in mind only the week limitations given by this technology.
In detail this work aims to highlight a new design strategy that consist of a combination of structural optimization tools (Topology Optimization TO) and non-contact stress field measurement technique (based on thermo-elasticity). The goal is to develop an iterative design procedures which links the design shape optimization with the experimental stress evaluation, allowing a wise material distribution in order to enhance the resistance.
The idea is to accomplish an initial designing phase, letting the designer free to define a first rough design concept taking into account the information provided by the TO to exploit the material in the best way. Then, the concept must be verified in both: model numerical F.E.M. analysis and prototype experimental evaluation of the stress field. Eventually, according to the verification analysis results, the model will be modified to reach the desired requirements in terms of allowed deformation, stress resistance and fatigue life.
The paper will display the optimization technique iterative process (based on Solid Isotropic Material with Penalization – SIMP – scheme) in a general way and through a practical example. As a reference, this methodology has been applied to a specific test case in order to design and optimize a new concept of a structural mechanical component of a mountain bike. The component was, first realized as a prototype in thermoplastic material and finally designed to be realized in metal for in field application.
