Rakesh Mishra

Numerical Analysis of Bird Impact on Glass-Reinforced Leading Edge of an Aircraft Wing

The paper describes the methodology of modeling and simulation of bird impact mechanism of GLARE laminate structures. The bird is modeled using Lagrangian concept. Explicit finite element techniques have been developed to simulate the impact mechanics. The study involves deeper understanding of impact dynamics and contact mechanics. The bird impact analysis has been carried out on typical configuration of GLARE 3/2, 4/3, 5/4, 6/5, 7/6 and 8/7. The results of stress propagation and material deformation at high strain rate have been obtained. Results from the numerical analysis are compared with experimental results, and the material is found to be capable of absorbing the impact energy. The results also show that the bird material model chosen to simulate for carrying out impact mechanics analysis is found to be capable of capturing most of the complex behavior exhibited by functional structural material GLARE.

Reliability Improvement in Aero Engines During the Infant Mortality Period of Operations

Aero engines exhibit typical product life cycle operational reliability characteristics of infant mortality, useful period before the final wear out phase. The reliability of operations during the infant mortality phase of operation of a newly designed, developed and productionized components or systems is always less compared to the other phases of its life. Critical examination of various defects and problems that arise during this phase indicates that the problems are mainly due to design deficiency compared to manufacturing, quality issues etc. Systematic and scientific resolution of these design-related reliability problems can go a long way in maturing the system and enhancing their availability for operation through the design life. This paper presents a scientific approach for addressing various infant mortality problems encountered in a turbo-shaft engine enabled with the state-of-the-art technology features. A critical design-related defect affecting adversely the operational availability of the engines for helicopters has been considered in the paper as the model for explaining the above approach. Such model can be adopted for resolution of typical design-related problems of aero engines and its systems for improving the reliability of operations.

Development of Reclamation Technology for a Turbo-Shaft Engine

Repair schemes for rectification of deviation and or defects in a turbo-shaft engine have been undertaken for sustaining reliability and availability of airborne equipments. A number of reclamation schemes have been developed and implemented successfully. This paper describes the common defects encountered in the aeroengine under study. The methodology for developing the reclamation scheme has been presented along with few case studies. These schemes have helped in maintaining the fleet effectively and avoiding costly rejections and turnaround time of the aeroengine.