Search for dissertations about: "Mohammad Afzal"

Found 2 swedish dissertations containing the words Mohammad Afzal.

2. 1. Numerical modelling and analysis of friction contact for turbine blades

   Author : Mohammad Afzal; Leif Kari; Viktor Berbyuk; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle and Maritime Engineering; Farkostteknik;

   Abstract : High cycle fatigue failure of turbine and compressor blades due to resonance in the operating frequency range is one of the main problems in the design of gas turbine engines. To suppress excessive vibrations in the blades and prevent high cycle fatigue, dry friction dampers are used by the engine manufacturers. READ MORE

4. 2. On efficient and adaptive modelling of friction damping in bladed disks

   Author : Mohammad Afzal; Leif Kari; Ines Lopez Arteaga; Muzio M Gola; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High cycle fatigue; Friction contact; Jacobian matrix; Shroud contact; Strip damper; Multiharmonic balance method; Contact stiffness; Cyclic symmetry; Nodal diameter; Magnetostrictive actuator; Magnetic field; Engineering Mechanics; Teknisk mekanik;

   Abstract : This work focuses on efficient modelling and adaptive control of friction damping in bladed disks. To efficiently simulate the friction contact, a full-3D time-discrete contact model is reformulated and an analytical expression for the Jacobian matrix is derived that reduces the computation time drastically with respect to the classical finite difference method. READ MORE