Mechanics of Composite Materials (FSI-RMO-A)

Academic year 2020/2021

Supervisor:	Ing. Zdeněk Majer, Ph.D.
Supervising institute:	ÚMTMB	all courses guaranted by this institute
Teaching language:	English
Aims of the course unit:
The objective of the course is to make students familiar with basic knowledge of mechanical behaviour of composite materials, especially of fibre composites. Elastic and strength characteristics of the composite are determined from the known mechanical properties of components and from their geometrical structure. Students get acquainted with methods used in evaluation of stresses, strains and safety factor of typical structures made of composite materials.
Learning outcomes and competences:
Students will have a clear idea of the directional behaviour of composite material and of methods used in stress-strain analysis and strength control of selected structures made of composite materials.
Prerequisites:
Knowledge of basic terms of theory of elasticity (stress, principal stress, deformation, strain, general Hooke's law), membrane theory of shells. Fundamentals of FEM and basic handling of ANSYS system.
Course contents:
Introduction, basic terminology. Mechanical properties of the most used fibres and matrix materials. Stiffness of unidirectional fibre composites (lamina) in longitudinal and transversal direction. Critical and minimum fibre volume fraction. Short fibre composites, theory of load transport. Transport and critical fibre length. Siffness and strength. Orthotropic behaviour as a result of the fibre composite structure. Hooke's law of the anisotropic, orthotropic and transversal orthotropic material in principal material directions. Hooke's law for 2-D fibre composite (lamina) in arbitrary direction, strength conditions. Constitutive relations of the laminated thin wall and thin plate. Construction of stiffness matrix, strength analysis. Application to the thin-wall pressure vessel.
Teaching methods and criteria:
The course is taught through lectures explaining the basic principles and theory of the discipline. Exercises are focused on practical topics presented in lectures.
Assesment methods and criteria linked to learning outcomes:
The credit conferment is based on the successful defence of the final project, dealing with computational modelling of mechanical behaviour of a defined structure made of composite material using FEM program ANSYS. The exam consists of a written review test and of an oral interview.
Controlled participation in lessons:
Attendance at practical training is obligatory. In a justified case an absence from the seminar can be compensated by individual projects controlled by the tutor.
Type of course unit:
Lecture	13 × 2 hrs.	optionally
Computer-assisted exercise	13 × 2 hrs.	compulsory
Course curriculum:
Lecture	1. Introduction. Fibres, matrix. 2. Manufacture and component form. 3. Basic characteristics of composites. Micromechanics. 4. Macromechanic. Clasical theory of laminates 5. Capability. Failure criteria. 6. Stability. 7. Sandwich structure. 8. Mechanical property, testing. 9. Properties of composite system. 10. Joining of composite structure. 11. Quality assurance. 12. Airworthiness considerations. 13. Structure Application. Tests.

Computer-assisted exercise	FEM simulation of tensile test of fibre composite specimen in longitudinal direction-verification of analytical equations. FEM simulation of tensile test of composite specimen in transversal direction-verification of analytical equations. FEM simulation of shear test of fibre composite specimen-verification of analytical equations. FEM simulation of longitudinal, tranversal and shear test of fibre composite specimen with exploiting homogenization. FEM computation of stress concentration factor in composite materials. Practical demonstration of production and testing of composite materials. Evaluation of final projects, credit.

Literature - fundamental:
1. Agarwal,B.D., Broutman,L.J.: Vláknové kompozity, SNTL Praha, 1987
2. Jones,R.M.: Mechanics of composite materials.,Hemisphere Publishing Corporation, New York, 1975
3. Krishan K. Chawla: Composite materials. Science and Engineering. Springer, New York, Berlin, 1998