College - Author 1

College of Engineering

Department - Author 1

Mechanical Engineering Department

Degree Name - Author 1

BS in Mechanical Engineering



Primary Advisor

Eileen Rossman, College of Engineering, Mechanical Engineering Department


The contents of this final design review (FDR) outline the progress made by a team of four mechanical engineering students at California Polytechnic State University, San Luis Obispo to solve the problem of torsional galloping in solar tracker panels since the preliminary design review. The project proposed by the sponsor, Christian Friedrich, on behalf of ARaymond is a design for a friction based braking system integrated into a redesigned bushing.

The CDR contains details about the system design, the design justification, the manufacturing plan, and design verification plan. In the system design section, the four manufacturing subsystems (bushing mount, actuation, power screw, and braking system) will be analyzed. This analysis will be expanded upon in the manufacturing plan where the current manufacturing plan for the project deliverable will be explained. The CDR will also detail any changes that have been made since the preliminary design review (PDR). Since the PDR, the frictional force that is needed to dampen the system has been adjusted to emulate the system more accurately. The project objectives are to dampen oscillation through frictional means, withstand gravitational and wind static loads of 7.5 metric tons, and endure wearing for 30 years.

The overall structure of the bushing has been altered in a variety of different ways. First, the outer journal has been completely separated into two parts to increase the available contact area for the band brake which permits multiple different band orientations to test. As a result, the inner journal has increased in axial length in accordance with the outer journal separation. The lever arm system has also been altered to allow the power screw to interface with the lever arm system. The lever arm system also straddles the I-beam support for ease of rotation and proper power screw engagement. In order to accommodate the separation between the outer journals, an additional mounting plate has been incorporated to mount both halves of the outer journal. Finally, the power screw has been re-oriented to be perpendicular with the I-beam to increase support and adjustability.