Crack Growth Prediction on Critical Component for Structure Life Extension of Royal Malaysian Air Force (RMAF) Sukhoi Su-30MKM

Abstract

The critical aircraft structure, being the load-bearing members, is a vital component for any aircraft. The effect of fatigue loading, operating conditions, and environmental degradation has caused the structural integrity of the airframe to be assessed for its airworthiness requirement. Using the fatigue design concept of Safe Life, the RMAF adopts the Aircraft Structure Integrity Program (ASIP) to monitor the structural integrity of its critical components. RMAF has produced the task card using the engineering analysis concept on the aircraft’s critical structure. Various Computer-Aided Engineering (CAE) methods were used, and for this analysis, the Crack Growth Prediction method was used to determine the crack growth behavior and its ultimate failure point in case of any crack occurrences. Although there are six critical locations, the wing root is chosen since it has the highest possibility of fatigue failure. The analytical methods which were discussed are Crack Growth Analysis and Low Cycle Fatigue. For the numerical method, NX Nastran was used for the simulation of crack growth. The result from the crack growth analysis was validated with the numerical result. The conclusion is that, based on the fatigue life cycle, the wing root structure condition is not affected by severe damage, and its failure is approximately around 30 to 100 years for both the through hole and through side crack. Thus, its structural life can be extended. The research outcome will be on the extension of the structure life of the aircraft wing.

Stochastic Modeling Of Fatigue Crack Propagation In Concrete Beams Using Markov Chain Simulation

“…In essence, Paris' law is used to estimate the rate at which a fatigue crack will advance in a material, which is essential for assessing the remaining useful life of structures and components subjected to cyclic loading, such as aircraft wings, pressure vessels, and pipelines [10].…”

Tensile Properties of Aircraft Coating Systems and Applied Strain Modeling

“…Loads to the coating system arise from displacements due to the relative motion of the aircraft skin and fastener heads in response to flight stresses. One high-stress location on airframes is located at the wing root [6], where the wing joins the aircraft body. A representative geometry was chosen that consisted of two aluminum plates and countersunk stainless-steel fasteners.…”

Empirical Modeling of Transverse Displacements of Single-Sided Transversely Cracked Prismatic Tension Beams

“…Many articles are devoted to the detection of cracks, the identification of crack parameters, and the further monitoring of their growth. They can be divided according to the structural elements (precast concrete members [6]) or structures they consider (dams [7], concrete structures [8] and bridges [9], pavements [10], as well as airplanes [11] and aircraft engine components [12]), or by the techniques and approaches used. Crack detection and identification were initially based on manual visual inspection of the structure.…”