PSI - Issue 14

K. Shridhar et al. / Procedia Structural Integrity 14 (2019) 375–383 Author name / Structural Integrity Procedia 00 (2018) 000–000

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a) From FE analysis SIF for different crack lengths are calculated by considering MVCCI method. b) SIF for the same crack lengths are calculated using analytical relations [8]: � ��� . √

��� ��� ��� ��� ��� ��� ���� ����

Where, ��� � �.�2 � � � � � � � � � � � � � � � � � � � � � � � 2 � 2 � � � � � �� �� � � � �� �� � � ��.22 � ��.�� � 2 � � � �.�� � 2 � � � � �.�2 � �.�2 � 2 � � � �.2� � 2 � � � � � �.�2� � � �.������� � � �

c) Stress intensity factors found using FE analysis are verified by analytical values. d) Crack length v/s Stress intensity factor graph is plotted. 5. Fatigue life estimation using Walker’s crack growth model.

There are many equations that can be used to determine the number of cycles to failure. Paris Equation is the most widely used. The only problem is that it is mainly applicable for very thin components or shells. Hence, the Walker Equation is used, as it gives accurate results for slightly thicker components that cannot be analysed by the Paris Equation. a) Fatigue crack growth life is estimated using Walker’s equation, � ��� � � � ��� � � ��2� [C =1.16Χ10 -9 m = 3.477 � � �.�2� ] Fatigue life of lug can be evaluated by integrating the crack growth rate relationship � � ��� � � � ��� � � � � � � ���� b) Crack length v/s Number of cycles is plotted.