Damage tolerance evaluation of wing in presence of large landing gear cutout ...eSAT Journals
Abstract Aircraft is symbol of a high performance mechanical structure, which has the ability to fly with a very high structural safety record. Aircraft experiences variable loading in service. Rarely an aircraft will fail due to a static overload during its service life. For the continued airworthiness of an aircraft during its entire economic service life, fatigue and damage tolerance design, analysis, testing and service experience correlation play a pivotal role. The present study includes the stress analysis and damage tolerance evaluation of the wing through a stiffened panel of the bottom skin with a landing gear cutout. Wing bottom skin experiences tensile stress field during flight. Cutouts required for fuel access and landing gear opening and retraction in the bottom skin will introduce stress concentration. Fatigue cracks will initiate from high tensile stress locations. An integral stiffened panel consisting a landing gear cutout is considered for the analysis. Stress analysis will identify the maximum tensile stress location in the panel. In a metallic structure fatigue manifests itself in the form of a crack which propagates. If the crack in a critical location goes unnoticed it could lead to a catastrophic failure of the airframe. A critical condition will occur when the stress intensity factor (SIF) at the crack tip becomes equal to fracture toughness of the material. SIF calculations will be carried out for a crack with incremental crack lengths using MVCCI method. Analytical evaluation of the crack arrest capability of the stiffening members ahead of the crack tip will be carried out. Index Terms: Key Aircraft, Design, wing, landing gear cutout, stress analysis, FEM, damage tolerance, integral stiffened panel.
Fatigue life estimation of rear fuselage structure of an aircrafteSAT Journals
Abstract Integrity of the airframe structure is achieved through rigorous design calculations, stress analysis and structural testing. Finite element method (FEM) is widely used for stress analysis of structural components. Each component in the airframe becomes critical based on the load distribution, which in-turn depends on the attitude of the aircraft during flight. Fuselage and wing are the two major components in the airframe structure. The current study includes a portion of the fuselage structure. Empennage is the rear portion of the aircraft, which consists of rear fuselage, Horizontal tail and vertical tail. The air loads acting on the HT also get transferred to rear portion of the fuselage. First step in ensuring the safety of the structure is the identification of critical locations for crack initiation. This can be achieved through detailed stress analysis of the airframe In this project one of the major stress concentration areas in the fuselage is considered for the analysis. Rear fuselage portion with a cargo door cutout region will be analysed. The structure considered for the stress analysis consists of skin, bulkheads and longerons, which are connected to each other through rivets. Aerodynamic load acting on the aircraft components is a distributed load. Depending on the mass distribution of the fuselage structure the inertia forces will vary along the length of the fuselage. The inertia force distribution makes the fuselage to bend about wing axis. During upward bending, bottom portion of the fuselage will experience tensile stress. A cutout region in the tensile stress field will experience high stress due to concentration effect. These high stress regions will be probable fatigue crack initiation locations in the current work, fatigue damage calculation will be carried out to estimate the fatigue life of the structure under the fluctuating loads experienced during flight. Miner’s rule will be adopted for fatigue damage calculation. Keywords: Transport aircraft, Rear fuselage, Cargo door, Finite element method, Stress concentration, Fatigue damage, Miner’ rule
CAPACITAR A LOS DOCENTES DE LA UNIVERSIDAD DE LOS ANGELES CAMPUS COMALCALCO EN LAS COMPETENCIAS BÁSICAS DEL QUEHACER DOCENTE EN EL AULA PARA PROMOCIONAR UN APRENDIZAJE SIGNIFICATIVO EN LOS ESTUDIANTES
Intake Meeting: Is it worth 30,000 of your time? DFWTRN
This is a TalentNetLive presentation I did for recruiters and sourcers at Capital One in Plano. TX.
The basic premise is that you have to 1) get managers invested in meeting with you prior to asking questions, 2) bring materials that show you are prepared and they should follow your lead, and 3) Use the intake to make sure you get buy-in on the process, and 4) Ask at least one push-back question, just to let the know you're there.
Damage tolerance evaluation of wing in presence of large landing gear cutout ...eSAT Journals
Abstract Aircraft is symbol of a high performance mechanical structure, which has the ability to fly with a very high structural safety record. Aircraft experiences variable loading in service. Rarely an aircraft will fail due to a static overload during its service life. For the continued airworthiness of an aircraft during its entire economic service life, fatigue and damage tolerance design, analysis, testing and service experience correlation play a pivotal role. The present study includes the stress analysis and damage tolerance evaluation of the wing through a stiffened panel of the bottom skin with a landing gear cutout. Wing bottom skin experiences tensile stress field during flight. Cutouts required for fuel access and landing gear opening and retraction in the bottom skin will introduce stress concentration. Fatigue cracks will initiate from high tensile stress locations. An integral stiffened panel consisting a landing gear cutout is considered for the analysis. Stress analysis will identify the maximum tensile stress location in the panel. In a metallic structure fatigue manifests itself in the form of a crack which propagates. If the crack in a critical location goes unnoticed it could lead to a catastrophic failure of the airframe. A critical condition will occur when the stress intensity factor (SIF) at the crack tip becomes equal to fracture toughness of the material. SIF calculations will be carried out for a crack with incremental crack lengths using MVCCI method. Analytical evaluation of the crack arrest capability of the stiffening members ahead of the crack tip will be carried out. Index Terms: Key Aircraft, Design, wing, landing gear cutout, stress analysis, FEM, damage tolerance, integral stiffened panel.
Fatigue life estimation of rear fuselage structure of an aircrafteSAT Journals
Abstract Integrity of the airframe structure is achieved through rigorous design calculations, stress analysis and structural testing. Finite element method (FEM) is widely used for stress analysis of structural components. Each component in the airframe becomes critical based on the load distribution, which in-turn depends on the attitude of the aircraft during flight. Fuselage and wing are the two major components in the airframe structure. The current study includes a portion of the fuselage structure. Empennage is the rear portion of the aircraft, which consists of rear fuselage, Horizontal tail and vertical tail. The air loads acting on the HT also get transferred to rear portion of the fuselage. First step in ensuring the safety of the structure is the identification of critical locations for crack initiation. This can be achieved through detailed stress analysis of the airframe In this project one of the major stress concentration areas in the fuselage is considered for the analysis. Rear fuselage portion with a cargo door cutout region will be analysed. The structure considered for the stress analysis consists of skin, bulkheads and longerons, which are connected to each other through rivets. Aerodynamic load acting on the aircraft components is a distributed load. Depending on the mass distribution of the fuselage structure the inertia forces will vary along the length of the fuselage. The inertia force distribution makes the fuselage to bend about wing axis. During upward bending, bottom portion of the fuselage will experience tensile stress. A cutout region in the tensile stress field will experience high stress due to concentration effect. These high stress regions will be probable fatigue crack initiation locations in the current work, fatigue damage calculation will be carried out to estimate the fatigue life of the structure under the fluctuating loads experienced during flight. Miner’s rule will be adopted for fatigue damage calculation. Keywords: Transport aircraft, Rear fuselage, Cargo door, Finite element method, Stress concentration, Fatigue damage, Miner’ rule
CAPACITAR A LOS DOCENTES DE LA UNIVERSIDAD DE LOS ANGELES CAMPUS COMALCALCO EN LAS COMPETENCIAS BÁSICAS DEL QUEHACER DOCENTE EN EL AULA PARA PROMOCIONAR UN APRENDIZAJE SIGNIFICATIVO EN LOS ESTUDIANTES
Intake Meeting: Is it worth 30,000 of your time? DFWTRN
This is a TalentNetLive presentation I did for recruiters and sourcers at Capital One in Plano. TX.
The basic premise is that you have to 1) get managers invested in meeting with you prior to asking questions, 2) bring materials that show you are prepared and they should follow your lead, and 3) Use the intake to make sure you get buy-in on the process, and 4) Ask at least one push-back question, just to let the know you're there.