Crimp is a term to describe the waviness of a fiber. We can also describe this in terms of the force or energy required to uncrimp a fiber. It’s expressed in percentage. A crimped fiber placed on a flat plane is l0 and the length of the same fiber when the crimp is removed by applying a tension is l, then the crimp is given by …
Instantaneous and time-dependent effect
When a load is applied on a specimen constantly for a period of time, the specimen initially extends rapidly giving the instantaneous effect and then less rapidly which yields to time dependent effect.
