Faculty Advisor

Cobb, Eben C.


A Variable Rate Shock Absorber system requires both an adjustable rate damper and spring. This project aimed to develop a coil spring for use with existing damper technology to allow fast and seamless transitions in the compression and rebound characteristics of an automotive suspension system. Various materials that are physically responsive to electrical stimuli were researched for the purpose of altering a coil spring's rest state with a net effect on the spring's behavior. Using mathematical models of spring characteristics, an ideal spring was designed for specific use with the chosen actuation medium. Testing methodology including data acquisition was developed to facilitate testing, refinement, and confirmation of project objectives and results. The final design is a linear rate coil spring whose rate can be varied through the application of a low current electrical power supply to a spring with an externally affixed layer of Nitinol.


Worcester Polytechnic Institute

Date Accepted

January 2003


Mechanical Engineering

Project Type

Major Qualifying Project


Restricted-WPI community only

Advisor Department

Mechanical Engineering