Applied Mechanics

n.a.

The teaching method of the course will be mostly student-centered, using structural components of daily use, which the student, alone or in a group, will have to analyze and understand, within the scope of mechanics concepts.

The bases for the introduction of the nuclear concepts involve the use of several types of methodologies of exposition and discussion. Thus, the following will be implemented:

– Exhibition of content using electronic presentations, to be made available to students as complementary documentation to support the UC;

– Visualization of multimedia content;
– Visualization of components and structural assemblies to support the UC.

Students will be presented with several challenges that contribute to the assessment process, contextualized in the various domains of the course. These challenges involve solving problems associated with understanding the functioning of some structural elements applicable in everyday life, as well as the design, development and construction of structural elements for defined objectives.

Also, exercises to apply each of the UC concepts will be solved, which will serve as a basis for the apprehension of knowledge and the development of challenges.

At the end of this curricular unit, students should be prepared to:

1 – Represent correctly the free body diagram of a rigid body subject to the action of one or more forces (concentrated forces, distributed forces and moment).

2 – Apply the static equilibrium equations correctly to a rigid body subject to the action of one or more forces (concentrated forces, distributed forces and moment).

3 – Determine correctly the reactions at the supports and pins of a rigid body subject to the action of one or more forces (concentrated forces, distributed forces and moment).

4 – Calculate correctly the internal forces acting on a given cross-section of a rigid body subject to the action of one or more forces (concentrated forces, distributed forces and moment).

5- Correctly calculate the location of the geometric centre of a compound plane area.

6 – Correctly calculate the moment of inertia of a compound plane area in relation to the axes passing through the geometric centre of the section using Steiner’s Theorem (Parallel Axes Theorem).

7 – Correctly calculate the static moment in relation to an axis passing through the geometric centre of a compound plane area.

8 – Critically analyse and evaluate the mechanical strength and rigidity of a mechanical structure subjected to the action of one or more forces (concentrated, distributed and moments).

9 – Comment on which material should be used, and the shape and dimensions of the most suitable cross-sections, to resist the various types of forces applied to a mechanical structure, at the lowest possible cost and with maximum safety.

1. Introduction

What is Mechanics? Fundamental concepts. Newton’s laws. International System of Units (SI).

2 – Static

2.1 – Mechanical action on a mechanical structure: forces (concentrated forces and distributed forces) and moment (moment of a force and torque ). Types of support of a structure.

2.2 – Degrees of freedom of a body. Static equilibrium of a mechanical structure: Degrees of freedom of a body. Types of support for a structure (mobile, fixed and embedded). Balance of a particle. Linear elastic spring. Cables and pulleys. Determining the reactions at the supports of an isostatic structure. Balance of a rigid body. Free body diagram. Determining the reactions at the supports of an isostatic structure – straight axis beam.

2.3 – Geometric properties of areas. Geometric center of a area. Moment of inertia. Steiner’s theorem. Polar moment of inertia. Cross section properties of some structural steel profiles.

3 – Basic Concepts of Strength of Materials

Stress concept: normal stress and shear stress. Concept of displacement and deformation. Resistance electric strain gauge. Hooke’s law. Stress diagrams – deformation for ductile and fragile materials. Concept of elasticity and plasticity. Mechanical properties of materials. Principle of Overlapping Effects of Forces. Potential Deformation Energy. Concept of Resilience and Tenacity of a material. Basic design of a mechanical structure. Notion of safety factor.

4 – Structural Elements subject to Axial Stresses

Stresses in bars axially loaded. Saint-Venant principle. Elongation of a bar with axial solicitation. Influence of temperature on the stretching of a bar. Statically undetermined structures.

5 – Structural elements subject to torsion

Pure shear. Twist on circular and non-circular sections. Study of thin-walled closed profiles. Twist in statically undetermined structures. Power transmitted by a motor to a shaft.

6 – Structural Elements subject to Bending

Relationships between distributed load, transverse force and bending moment. Transverse and bending moment diagrams for straight axis structures. Bending of straight-axis beams: pure bending, simple bending. Normal compressive and tensile stresses. Neutral line equation. Shear stresses in bending. Static moment for a circular, rectangular, T-shaped and I-shaped cross-section.

The curricular unit operates in two possible regimes: a) Continuous assessment; b) Assessment by final exam.

By the second week of classes of the semester, the student chooses the assessment regime they wish to follow in the course.

a) Continuous Evaluation

In the continuous assessment regime, the curricular unit incorporates the following:

Tests: 60%, compulsory minimum mark of 9. Compulsory assessment element.
Two written tests, with a minimum mark of 7.5 for each test, in the form of theoretical-practical case studies, to be carried out during classes. Each test has a weight of 35 per cent.

Case studies: 40%, with no minimum mark. No use of AI is permitted.
Carrying out a set of case studies that may involve experimentation, oral presentation and discussion, to be carried out individually or in groups, and during classes. The case studies will be presented in the form of a written report (handwritten or word processor format) or other means of communication and exposition, such as a poster.

Final classification (continuous assessment): Tests*60% + Case Studies*40%

b) Evaluation by Final Exam

Exam: 100%, minimum mark of 9.5. Compulsory assessment element. No use of Artificial Intelligence (AI) is permitted.

Final classification (Exam) : Exam*100%

c) Exclusive assessment for student workers

Students with student worker status may opt for any of the assessment methods mentioned in the previous point, or if they don't want to, the following assessment regime applies

In the continuous assessment system, the course incorporates the following:

Exam: 70%, compulsory minimum mark of 9.5. Compulsory assessment element. No use of Artificial Intelligence (AI) is permitted.
Case studies: 30%, no minimum mark. No use of AI is permitted.
Carrying out a set of case studies that may involve experimentation, oral presentation and discussion to be carried out individually or in groups, and in the course of lessons. The case studies will be presented in the form of a written report (handwritten or word processor format) or other means of communication and exposition, such as a poster.

Final classification: Exam*60% + Case Studies*40%

NAO