Load apparatus and method for bolt-loaded compact tension test specimen

A bolt-loaded compact tension test specimen load apparatus, the specimen having a notch and a threaded opening extending to and positioned transversely relative to the notch for receiving a threaded bolt for applying an opening force to the notch, the load apparatus comprising:

• a body having first and second opposing longitudinal ends, the first end comprising an externally threaded portion sized to be threadedly received within the test specimen threaded opening;
• a longitudinal loading rod having first and second opposing longitudinal ends, the loading rod being slidably received in a longitudinal direction within the body internally through the externally threaded portion and slidably extending longitudinally outward of the body first longitudinal end;
• a force sensitive transducer slidably received within the body and positioned to engage relative to the loading rod second longitudinal end;
• a force transfer plate slidably positioned within the body between the loading bolt and the transducer;
• and
• a loading bolt threadedly received relative to the body, the loading bolt having a bearing end surface and being positioned to bear against the transducer to forcibly sandwich the transducer between the loading bolt and loading rod.

A method of in situ determination of applied force during crack propagation in a bolt-loaded compact tension test specimen, the method comprising the following steps:

• providing a rod in a transversely slidable orientation relative to a notch in a bolt-loaded compact tension test specimen, the rod having first and second opposing ends, the first end being positioned and adapted for bearing against one transverse surface of the test specimen exposed by the notch;
• providing a force sensitive transducer operatively against the second end of the loading rod;
• threading a bolt operatively against the transducer to force the first rod end against the one transverse surface of the test specimen to load the test specimen;
• and
• determining applied force on the test specimen as a function of time from readings obtained from the force sensitive transducer.