It was conducted on Wednesday, 25/10/2023, in the meeting hall the discussion of the master’s thesis of the student Safa Ali Mahmood, which is tagged:
” Formulation of camshaft Dynamic Load Factor under Uniform and Harmonic Excitations “.
The discussion committee consisted of names listed below:
1- Prof. Dr. Fathi Abdul sahib. Al-shamaa (Chairman)
2- Asst. Prof. Dr. Hamza Abdul Rasoul Hussain (Member)
3- Asst. Prof. Dr. Tariq Mohmmad Hamza (Member)
4-Asst. Prof. Dr. Nassear Rashied Hamoad (Supervisor)
The aim of the thesis was to investigate the performance of different cams using three aspects: analytical, numerical and experimental. The dynamic performance of the harmonic and uniform acceleration cam-follower system with roller contact mechanism was examined based on the produced dynamic forces. The camshaft was considered in the present work as simply supported beam using continuous beam theory. Accordingly, the steady state dynamic deflection is extracted as the solution of fourth order partial differential equation to be used in the evaluation of the dynamic load factor. Numerically, Finite element method has been adopted to simulate the static and dynamic contact stresses, and dynamic load factor for single element camshaft and multi-elements camshaft. Experimentally, investigating the static maximum contact stress that occurs on cam surface at the area of contact with the follower using photoelastic technique.
Accordingly, the thesis included recommendations including:
- The dynamic contact stress can be reduced by about (26) % for harmonic cam and (28) % for uniform acceleration cam based on follower mass reduction.
- The dynamic load factor has been positively affected by increasing follower stiffness, the enhancement percentage was (90) % for harmonic cam and 87% for uniform acceleration cam.
- The follower which has harmonic motion is more sensitive to separation than follower which has uniform acceleration motion.
After the scientific discussion by the members of the discussion committee, the researcher received a rating of (very good).
