Machine Design 2

Synthetic program:

COSTRUZIONE DI MACCHINE 2
I principali contenuti del corso sono:
• Analisi stato di sforzo 3D in componenti meccanici complessi
• Il passaggio dal calcolo strutturale alla verifica di resistenza statica ed a fatica
• I criteri di accettabilità di elementi con difetti
• Applicazioni a componenti e strutture meccaniche.

Structural Analysis.
Statically undetermined systems: Force Method Axisymmetric problems: Thin and Thick Cylinders loaded by internal and external pressure and centrifugal loads. Finite element modelling: basic formulation, definition of stiffness matrix, main shape functions, selection of element types, load and boundary conditions, evaluation of results, type of analysis (static, dynamic, etc.)

Strength of materials and assessment criteria
3D state of stress, multiaxial failure theories Cyclic response of materials: High Cycle Fatigue. Endurance limit, Fatigue strength, Modifying factors, Stress Concentration and Notch Sensitivity, Multiaxial Fatigue, Variable Amplitude loading, Cumulative Fatigue damage Linear Elastic Fracture Mechanics: energy approach (Griffith), Stress Intensity Factor, KIC, Fatigue Crack. Propagation

Design of Machine Elements
Shaft and Shaft Components. Materials, layout, design for stress, deflections, critical speeds, components, fits. Welding and the Design of Permanent Joints. Stresses in Welded Joints, Strength of Welded Joints.

Case Studies
The first case study will be based either on Railway Axle application or on a Power Transmission Gearbox application depending on the class. In both cases it will include General Analysis, Design of Shafts, Shrink Fits and Fatigue Assessment.
The second case study will be a Pressure Vessel, with the Validation of Analytical Methods by Means of FEM analysis and Lab Tests.