PSI - Issue 14

K. Shridhar et al. / Procedia Structural Integrity 14 (2019) 375–383

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K. Shridhar et al./ Structural Integrity Procedia 00 (2018) 000–000

3. Stress analysis of aircraft lug A geometrical non-linear static stress analysis has been carried out for the lugs with different radius ratios to identify location, magnitude of maximum stresses and to investigate the effect of radius ratio on stress concentration factor. The primary intension of stress analysis is to identify maximum tensile stress location because it is the possible location of crack initiation. 3.1. Effect of radius ratio on stress concentration. The pin loaded lug is analyzed for 1.5, 2 and 3 radius ratios by varying inner radius of the lug to check the effect on stress concentration.  A non-linear static stress analysis will be carried out to find maximum stress (σ max ) and to identify the maximum stress location.  The SCF will be found using the relation: � � ��� �� �1� Where, �� � 2 � � � �2�  The K t found using FE analysis will be verified by analytical relation [1] : � � �2��5 � 1 35 � � � � � 1� �������� �� � �� � �3� 4. Stress intensity factor solutions of cracked pin loaded lug. In general, geometry of notched structural components and loading is too complex for the stress intensity factor (SIF) to be solved analytically. The SIF calculation is further complicated because it is a function of the position along the crack front, crack size and shape, type of loading and geometry of the structure. In this work analytical results and FEM were used to perform linear fracture mechanics analysis of the pin-lug assembly. Based on the stress intensity factors, fatigue crack growth life predictions have been investigated. The lug dimensions are defined in Fig 2.

Fig 2.General parameters of lug with through the thickness crack