Table of Contents

Fracture resistance: Experimental methods

This page provides the introduction to experimental methods used for characterization of fracture resistance in this repository.

Three-point bending of IACSB specimen

The Inclined Edge Cracked Semi-Circular Bend (IACSB) specimen, in comparison with others, gives the opportunity to cover a wider range of the stress intensity factors (KI and KII) and T-stresses, without requiring a complex loading setup. The testing methodology based on the IACSB samples also utilizes the capability of the AM processes to build 3-D notches that act like artificial cracks, which opens possibilities to study crack propagation in selected directions.

Specimens

The IASCB specimen, shown in the figure below is a semi-circular disk of radius R and thickness t which contains a radial edge crack of length a, tilted with respect to the load direction of an angle α.

Loads

To conduct the fracture tests, a specimen is positioned on two bottom supports and loaded by a vertical force P (figure above). Different values of geometric parameters S1, S2 and R allow for simple realization of various combinations of Mode I and Mode II fracture modes. The geometrical parameters which can be varied to achieve mixed mode (I and II) are:

  1. S1/R and S2/R (the ratio between the support spans and the specimen radius);
  2. a/R (the ratio between the crack length and the specimen radius);
  3. α (the angle between the crack line and the load direction).

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