There are two methods of experimenting Tensile properties of a textile material. and they are ;
1. CRL method ( constant rate of loading )
2. CRE method (constant rate of elongation)
1. CRL method: The function of applied force is to extent the specimen until it eventually breaks down. Here the loading causes the elongation.
By adding constant rate of water flow in a container which is attached with the jaw J2 may increase the load gradually. Thus constant rate of flow gives constant rate of loading.
2. CRE method: A specimen A is gripped between two jaws. J1 is fixed and bottom jaw J2 is movable to down-ward at constant velocity by mean of a screw mechanism. Initially the tension on A is zero. But when the bottom jaw J2 moves down-ward at a constant rate the specimen is extended and an increasing tension is developed until it eventually breaks down. Here the elongation /tension causes loading.
Difference between CRL & CRE methods
1. CRL means Constant rate of loading.
|1. CRE means Constant rate of elongation.|
|2. This method contains container and water flow used to increase load gradually.||2. This method contains screw mechanism.|
|3. In this method loading causes elongation.||3. In this method elongation/ extension causes loading.|