Machine Elements II
Faculdade de Ciências e Tecnologia
Departamento de Engenharia Mecânica e Industrial
Teacher in charge
António Manuel Flores Romão de Azevedo Gonçalves Coelho, Rui Fernando dos Santos Pereira Martins
The main objectives of Machine Elements II are:
1. Know how to use the graphical and semi-graphical methods for determine the displacement, velocity, acceleration and forces applied on mechanisms.
2. Know how to determine displacement, velocity, acceleration and forces on mechanisms elements using numerical packages included in engineering simulation software, such as: SolidWorks, Motion and Simulation.
3. Use graphical methods to perform mechanism synthesis/design;
4. Calculation of axisymmetric pressure vessels and piping using the theoretical formulation and the Design Standards ASME Boiler and Pressure Vessels Code, Section VIII, Division 1 and BS 5500 - Specification for unfired fusion welded pressure vessels.
5. Know how to manufacture pressure vessels, including cut, bending and welding of the materials. Stress relief treatments, as well as non-destructive testing, will be described.
6. Know how to calculate the hydrostatic pressure test value and the detailed procedures to perform the test.
7. Plates: Stress and strain distribution using the Navier and the Ritz Methods.
Notes: Students will develop thecnical writing skills and also teamwork capacities with the elaboration of laboratory and numerical reports, besides the knowledge acquired with the software use.
No special requirements are needed.
Mechanism and Machine Theory: Graphical methods for displacement, velocity and acceleration analyses of mechanisms. Graphical methods for mechanism synthesis with 2, 3 and 4 coordinate positions. Machines’ kinetostatics and dynamics. Numeric simulation of mechanisms using engineering simulation software, such as: SolidWorks, CosmosMotion and Simulation/Ansys.
Pressure vessels: Calculation of axisymmetric pressure vessels and piping. Introduction to Design Standards ASME Boiler and Pressure Vessels Code, Section VIII, Division 1 and BS 5500 - Specification for unfired fusion welded pressure vessels.
Theory of Plates: Stress and strain distribution using Navier and Rayleigh Ritz Methods.
Schwamb, P., Merril, J. & Doughtie, "Nociones de Mecanismos", Ed. Aguilar S.A. (1985)
Bednar, Henry H., "Pressure vessel design handbook", Ed. Van Nostrand Reinhold Company (1991)
Ugural, Ansel C., "Stresses in plates and shells", 2a Edição, McGraw-Hill International Editions (1999)
Advanced Strength of Materials, den Hartog, McGraw-Hill
The oral exposition is essentially the teaching method used, associated with sketches, schemes and resumes made by the teacher in the classroom blackboard. The video projector is also used in the classroom.
The teacher solves representative problems first to introduce the students to the problem strategies of resolution. Then some problems are presented and a time period is fixed to the resolution. The teacher will attend any doubts during this period. All problems are solved in the blackboars classroom and commented.
The lab experiments have two main objectives, namelly: to compare the theoretical with the experimental/numerical results; to give the students the possibility to gain some pratical experience. The lab reports should be the more complete as possible and also concise and objective.
The evaluation in Machine Elements II will be performed by two tests, NT1 and NT2, and by two experimental/numerical works, NTL and NTC, during the semester. In addition, the Test no.1, NT1, and the laboratorial work, NTL, will be done till the 8th week of the semester.
The laboratorial work will be done individually and the computacional work will be done in group, being allowed 2 students per group. The classifications obtained in the numerical/experimental works are valid for one year.
The admittance to the exam will be ok if a classification higher than 9.5 is obtained by the student in each practical/numerical work, NTL and NTC, in a 0 to 20 scale.
The final classification (NF) will be determined by the formula:
NF=0.25xNT1+0.25xNT2+0.25xNTL+0.25xNTC (with NT1 >= 9.5 and NT2 >= 9.5)
During the Tests no.1 and during the Exam it is possible to consult a formulary of two manuscript pages only related to the plates and shells theory.
In case of not being approved in a test during the semester, the student will be allowed to go to the exam if he obtained frequency. The exam will be divided in two parts - Exame(NT1) e Exame(NT2) corresponding to the two parts of the program that was evaluated by the two tests.
In case of the students that will make the exam, the final classification (NF) will be determined by the formula:
NF=0.25xExame(NT1)+0.25x Exame(NT2)+0.25xNTL+0.25xNTC (Exame(NT1) and Exame(NT2) >= 9.5)