PSI - Issue 24

Dario Fiumarella et al. / Procedia Structural Integrity 24 (2019) 11–27 Dario Fiumarella/ Structural Integrity Procedia 00 (2019) 000–000

20 10

The load-stroke trend of the bias-extension test is plotted in Figure 8. However, the global parameters obtained from this test are insufficient to evaluate the shear properties. Accordingly, geometrical considerations must be introduced to evaluate the shear behaviour of the specimen (Launay et al. 2008). In the undeformed configuration, it is possible to write the length of the side edge of the zone C (Figure 6) as in equation (1): � � � � √ 2 2 (1) where � � � � � (2) If the length is exactly the double of the width, the equation (2) becomes � � � (3) When a load is applied, the length of the specimen is extended of d . The A zones (Figure 6) are undeformed, and therefore only the H distance changes: � � � � 2 � � ���� � (4) Consequently, it is possible to evaluate the angle (Figure 6) as follows: � ��� �� � � � � � �� � �� � √2 (5) The shear angle in the zone subjected to pure shear (zone C) can be evaluated with the equation (6): � 2 � 2 (6) Considering the parameter d as the stroke obtained during the bias-extension test, it is possible to plot the shear angle as a function of the applied load, as shown in Figure 9.