The subject Machine Design is studied in the sixth semester of the Degree in Mechanical Engineering, is a four months subject. Is complemented with the subject Kinematics and Dynamics of Machines, in the fifth semester. For tracking the course are necessary basic knowledge of mechanics acquired in the subject Applied Mechanics in the second year and resistance of materials acquired in the subject Elasticity and Strength of Materials in the fifth semester.

Knowledge of machine elements will be of great interest for the optional subject Computer Aided Structural Analysis and for the realization of the end of Degree Project.

The subject Machine Design is for the graduate in Mechanical Engineering, an introduction to the world of industrial machinery and is an important tool for the development of labor activity related to the machinery and its operation, both in design activities, construction base, maintenance or marketing.

In the first part the basic principles are studied in the engineering design of machines, study of stresses and fault conditions considerating static and dynamic loads, and the study of different criteria for predicting failure in a part, known loads that it will bear.

In the second part, the description and calculation of machine elements is faced. Different mechanical elements commonly found on machines are studied: Support elements in shafts such as bearings, power transmission elements such as gears, belts or chains, coupling elements such as feather keys. Guidelines for the design are discussed, considering different aspects such as strength, durability, manufacturing and assembly.

Know, understand and apply the fundamentals of Machine Design, so that enable students for the subsequent application of advanced methods and theories, in their professional development in areas of the Engineering Mechanics and likewise will provide themselves with great versatility for adapt to new situations.

Apply properly the strategies of scientific methodology: analyze qualitative and quantitative problem situations; hypothesizing and solutions for solving problems of Machine Design in the field of mechanical engineering. Understand and interpret the results.

Express correctly, using appropriate means, theoretical knowledge, solving methods, results and aspects inherent to the problems posed by the calculation, construction and testing of machines, in mechanical engineering, using the specific vocabulary and terminology of the subject.

Work in groups effectively integrating skills and knowledge to formulate ideas, discuss proposals and decisions on the development of their own works of Machine Design and in the field of mechanical engineering.

Develop designs, projects and processes in the field of Machine Design, and within the field of mechanical engineering. And also make measurements, calculations, studies, reports and other similar work-related problem situations that may arise in the field of specialty.

Know, understand, interpret and apply correctly, the laws, specifications, regulations and mandatory standards in Machine Design, within the field of mechanical engineering.

Chapter 0.- Overview on design and mechanical analysis.

0.1.- oPlanning and rganization of the course

0.2.- Program of the course.

0.3.- Current status of the analysis and design of machines.

0.4.- Relationship with other subjects.

0.5.- Codes and standards.

0.6.- Units.

Chapter 1.- Introduction to machine design.

1.1.- Design criteria.

1.2.- Design and analysis of machines: rough calculations, FEM, prototypes.

1.3.- Selection of materials: qualitative and quantitative properties.

1.4.- Safety factor in machine design.

Chapter 2.- Static stress calculations.

2.1.- Local effects: stress concentration.

2.2.- Static failure theories machine design.

2.3.- Factors that promote brittle failure in ductile materials.

2.4.- Introduction to fracture mechanics.

Chapter 3.- Fatigue of materials in mechanical design.

3.1.- Fatigue tests; Fatigue limit.

3.2.- Factor that modify the fatigue limit.

3.3.- Concentration of stresses in fatigue.

3.4.- Effect of the non-zero mean stresses.

3.5.- Cumulative damage; Palmgren-Miner method.

3.6.- Fatigue analysis with multiaxial stresses.

Chapter 4.- Introduction to Finite Elements Method (FEM).

4.1.- Brief historical overview.

4.2.- Intuitive basis.

4.3.- Field of application.

4.4.- Properties of the elements.

4.5.- Organization of a Finite Element program: preprocessor, processor and postprocessor.

Chapter 5.- Design of shafts and associated parts.

5.1.- Introduction.

5.2.- Dimensioning of shafts: static and fatigue.

5.3.- Design of other elements associated to shafts: couplings, keys, bolts and pins.

5.4.- Some aspects to consider when designing axes.

5.5.- Redesign of crankshafts.

Chapter 6.- Calculation of gears.

6.1.- General information on gear design.

6.2.- Calculation Module: Lewis formula.

6.3.- Checking module to resistance.

6.4.- Checking module to wear.

Chapter 7.- Belt drives.

7.1.- Introduction y classification.

7.2.- Behavioral model of belts.

7.3.- Design belt drives.

Chapter 8.- Clutchs, brakes and screws.

8.1.- Function and types of clutches.

8.2.- Friction clutches.

8.3.- Approach to the problem of braking.

8.4.- Brake calculation: tape and disk shoe.

8.5.- Screws for power transmission; ballscrews.

Chapter 9.- Bearings.

9.1.- Different types. Nomenclature. Characteristic elements.

9.2.- Static load and dynamic. Equivalent load.

9.3.- Durability of bearings.

9.4.- Choosing bearings. Using catalogs.

9.5.- Bearings with Hydrodynamic and hydrostatic lubrication.

Chapter 10.- Experimental methods in machine design.

10.1.- Types of tests.

10.2.- Measuring instrumentation.

10.3.- Tests with static and fatigue loads.

10.4.- Vibratory tests: natural frequencies, damping and vibration modes.

10.5.- Monitoring and diagnostics of machines.

In the lectures the theory is explained and related examples are solved. In the classroom practices can be explained theoretical concepts and provide exercises to develop.

A work will be proposed for each group. The focus will be on any of the items corresponding to points 7 to 10.

Groups should define the conditions of influence and demands to be achieved.

Should be known:

- The machine / device mounting location.

- Terms of Service. Requirements.

- Commercial data.

Depending on the element or elements chosen for the design, should be investigated:

- Loads, types and magnitudes.

- Speeds, transmission ratio.

- Mounting room.

- Ambiental conditions.

- Rigidity of the adjacent parts.

- Life.

- Precission.

- Noise.

- Friction and service temperature.

- Lubricationn y manteinance.

- Mounting and dismounting.

- Power to transmit.

Results should be exposed at class.

• Final Assessment System
• Tools and qualification percentages:
  • Written test to be taken (%): 60
  • Realization of Practical Work (exercises, cases or problems) (%): 30
  • Team projects (problem solving, project design)) (%): 10

The written test to develop will have a value of 60%.

Elaboration of a written test based on theoretical and practical knowledge which are assessed to the level of analysis.

And as stated in the management regulations for degree courses in Article 39. Training program and teaching guides:

Regardless the assessment method, if performing a final test involving at least 50% of the total mark of the subject is contemplated, not to run this test constitute a waiver of the notice of assessment and must recorded as a not examined.

The group work has a value of 30% of the final grade will be taken into account for the evaluation of the work:

- The document: Its quality and the skills developed in the group work (minutes, tutoring, contact hours).

- Presentation: Evaluation of fellows, teacher assessment, attendance and participation.

To pass the subject is necessary to pass independently both the examination and group work. If pass one of the two parts (examination or work) in May session, note that part will be saved until the July session. Failure to pass the written test will be the final mark of the examination, regardless of the job.

Practical work 10%

Delivery of reports made in group practices, evaluating the quality of reporting.

Same than in the ordinary examination.

Teacher notes. Theory, problems, tables and graphs (E-gela).

Basic bibliography

SHIGLEY, S.E. : "Diseño en Ingeniería Mecánica".

Robert. L. Norton. "Diseño de Maquinaria".

Robert L. Mott "Diseño de Elementos de Máquinas".

Carlos Angulo, Luis Norberto López de Lacalle, Josu Agirrebeitia, Charles Pinto. "Elementos de Máquinas".

R. Avilés. "Análisis de Fatiga en Máquinas".

R. Avilés. "El método de los elementos finitos en Ingeniería Mecánica".

M.F. Spotts. "Proyecto de elementos de máquinas".

In-depth bibliography

NORTON: "Diseño de máquinas"
LUIS GARCIA PASCUAL: "Teoría de máquinas".
MOTT.:"Diseño de elementos de máquinas"
G.NIEMANN.:"Elementos de máquinas".

Journals

Electronic Journals for Mechanical Engineering.- Mechanical Engineering Education.- Journal of Mechanical Design.- Journal of Mechanical Engineering Science.

Web addresses

http://moodle.ehu.es http://www.aenor.es/
http://www.skf.com/
http://www.geartechnology.com/
http://www.indarbelt.es/
http://www.infomecanica.com/
http://www.cadersa.es/