Summary: | Fracture toughness testing becomes a very important parameter for mechanical design and maintenance of parts and structures. This work presents the design and construction of a machine device to perform the pre-crack nucleation on SE(B) specimens for fracture toughness testing. Employing this device, it is possible to test materials for K Ic, CTOD and J Ic in a conventional tensile test equipment, assisted by a data acquisition system. The device is based on the concept of loading from an eccentric mechanism, controlling the displacement by means of a marking ring. The main contribution of this work is the low cost technology offered for laboratories, without high priced servo-hydraulic testing machines, giving them autonomy for the execution of fracture toughness tests. The experimental results satisfied the expectation about crack nucleation on SE(B) and applied loading control.
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