Design, analysis and evaluation of composite suspension arms for competition automotive application

• Main Author: Κώστας, Θεοφάνης
• Other Authors: Kostas, Theofanis
• Language: English
• Published: 2023
• Subjects: Suspension arms; Composites; Automotive; Σχεδιασμός ανάρτησης; Σύνθετα υλικά; Τομέας αυτοκίνησης; Αγωνιστικές εφαρμογές; Βραχίονες ανάρτησης

The scope of this thesis is the utilization of classical mechanics and statics, mechanics of composites and strength of materials and also essential design axioms to conceptualize, iterate, verify and then materialize a complete double wishbone independent suspension system, appropriate for an automotive application and more specifically, motorsports. Firstly, an appropriate physical layout will be chosen, one that complies with the physical constraints imposed from the rest of the vehicle that adheres to the desired spatial planning and one that also utilizes in the best of the possible ways enough adjustability, low weight, low center of weight, suspension articulation, steering articulation and more design targets. Also, the pure kinematics design parameters will be discussed and why these are to be desired, meaning how the characteristics of the tire can be translated through the suspension system so the contact patch can be maximized through the whole suspension articulation , so the grip and ultimately the vehicles performance can be maximized . Then , maximum load case scenarios will be established , by appropriate estimation of mechanical and aerodynamic loads acting on the center of the weight and center of aerodynamics of the vehicle , reacted through the tire contact patch and ultimately , through the suspension. For this, a code implemented analytical tool will be written in Matlab so the loads can be distributed appropriately in the four corners of the vehicle and each individual worse load case scenario can be accessed. For the establishment of each suspension arm individual load a statics problem will need to be solved for each load case scenario and also through suspension articulation, so it is also crucial to utilize a Matlab code implemented tool for solving the resultant spatial static equations effortlessly. After the estimated loads are defined, each individual suspension arm design will be refined and iterated by the use of CAD, appropriate material and construction method will be chosen and it will be subjected to stress and fatigue finite element analysis .At this point appropriate load bearing hardware will be dimensioned, like bolts, nuts, bearings, tie rods, and the design process thought and considerations will be discussed. Next, the benefits of composite materials in this application will be investigated, by appropriately designing the material and the geometry of alternative, carbon fiber composite suspension arms, in an effort to maximize performance by reducing the weight even further through application of Composite mechanics. The complexity and drawbacks of each consideration will be discussed and also the assumptions, design limitations and the benefits of each system will be explained. In summary, this thesis aspires to cover the majority of design considerations and desired attributes a competition automotive suspension system must adhere to, structurally wise and to give insight to what a final implementation both of commonplace materials and cutting edge solutions, like carbon fiber reinforced polymers, can be.