Dynamics of Rigid Bodies


The students that have successfully completed this curricular unit have demonstrated ability to:

-Understand the fundamental concepts and principles that form the basis of Kinematics and Dynamics of particles and rigid bodies; 

-Apply the fundamental concepts and principles to analyze the kinematics of simple mechanisms, consisting of a limited number of rigid bodies;

-Apply the fundamental concepts and principles to analyze the dynamics of simple mechanisms, consisting of a limited number of rigid bodies;

-Understand and analyse the vibrations of undamped and damped rigid bodies and structures with one-degree-of-freedom.


General characterization





Responsible teacher

Corneliu Cismasiu, Zuzana Dimitrovova


Weekly - 4

Total - 70

Teaching language



The students should have the course of Statics completed. It is strongly recommended to those without this condition to unsubscribe.


[1] F. P. Beer and E. R. Johnston Jr. 
Vectorial mecânics for engineers: Statics
Editora McGraw-Hill de Portugal, 7ª Edição, 2006.

[2] F. P. Beer and E. R. Johnston Jr. 
Vectorial mecânics for engineers: Dynamics.  
Editora McGraw-Hill de Portugal, 6ª Edição, 1998. 

Teaching method

All matters of discipline are covered in problem-solving sessions.  

The exhibition and explanation of various concepts, principles and methods is exemplified with the resolution of some illustrative problems.  

A discussion of the problems posed is promoted and students are encouraged to solve some problems individually.

Evaluation method

Conditions of obtaining:
Attendance of at least 2/3 of the classes (except for students with frequency obtained in 2018/2019 and students with statutes excusing from class attendance).

assessment consists of two tests, of duration of 1.5h. Problems of these tests may involve some theoretical questions. Test ratings (T1, T2) will be rounded to 1 decimal place.

Students may choose to take the full exam within 3 hours or to improve one of the tests within 1.5 hours. This option will be communicated to the teacher at the beginning of the test and will be irreversible.
In the case of improvements, the improved rating will replace the corresponding test rating (Ti).
The exam grade E will be rounded to 1 decimal place.

Overall rating
The overall rating (N) will be calculated as follows:
N = Max (E, (T1 + T2) / 2)

Registration for the tests and exam is required. According to the assessment regulation: “If 10 minutes after the actual start of the test, there are enough places (respecting the necessary spacing) in the examination room for the whole group of non-registered students who still wants to take the test, then all of them will be admitted without the right to time recovery. If there are not enough places for the whole group, then none of them will be admitted”.

Absence justifications
Justifications for absences must be accompanied by the generic requirement that can be obtained online or at the academic division.

Subject matter

1. Mass moments of inertia of bodies in 3D.

2. Virtual Work Method: The work of a force; Principle of Virtual Work; The work of a force through a finite displacement; Potential energy; Potential energy and equilibrium.

3. Kinematics of rigid bodies: Translation; Rotation about a fixed axis; General plane motion.

4. Dynamics of rigid bodies: Equations of motion; Principle of conservation of energy.  

5. Mechanical vibrations: Undamped vibrations; Damped vibration.


Programs where the course is taught: