Course details

Mechanics of Composite Materials

Teaching: Completely taught in English

ECTS: 3

Level: Graduate

Semester: Summer

Prerequisites:

Load:

Lectures	Exercises	Laboratory exercises	Project laboratory	Physical education excercises	Field exercises	Seminar	Design exercises	Practicum
30		0	0	0	0	0	0	0

Course objectives:

Familiarization with basic expressions and methods used in stress analysis of composite structures.

Student responsibilities:

Attendance at lectures; attendance at exercises; successful and regular passing of partial exams; student assignment;

Grading and evaluation of student work over the course of instruction and at a final exam:

70% written partial exams during the semester; 30% independent work on the student assignment

Upon successful completion of the course, students will be able to (learning outcomes):

1 . Solve the problems related to the definition of the basic mechanical behaviour and failure processes of nonisotropic laminated materials.

2 . Apply advanced methods used in their strength analysis and the structural behaviour due to increased temperature and moisture.

3 . Assess the available analytical methodology which is used in the field of mechanical analysis of composite structures.

4 . Develop the ability for critical analysis of the mechanical behaviour of composite structures and the correct validation of the results obtained using the analytical methodology

Lectures

1. Mechanical properties of fibre and matrix. Classification of composites. Types of reinforcement. Nomenclature.

2. Fundamental equations of micromechanics. Rule of mixtures. Halpin-Tsai equations. Expressions based on theory of elasticity.

3. Fundamental equations of macromechanics. Derivation of elasticity tensor symmetry.

4. Elasticity matrix of an anisotropic, orthotropic, isotropic, transversely isotropic material.

5. Transformation of mechanics properties at main material axes rotation.

6. Constitutive equation of composite materials. Derivation of A,B,D matrices.

7. Analysis of symmetric, anti-symmetric and other layering setups.

8. Stresses and strains in layered composites.

9. Thermal properties of composite phases. Thermal stresses in composites. Influence of manufacturing.

10. Failure criteria. Maximum stress criterion. Maximum strain criterion. Tsai-Wu criterion. Tsai-Hill criterion. Special failure criteria - Hashin"s criterion.

11. First-ply failure and last-ply failure criteria.

12. Damage in composites. Fiber breakage. Matrix cracking. Pull out. Delaminations.

13. Joints in composite structures.

14. Specifics of finite element analysis of composite structures.

15. Examples of composite structures.

Exercises

1. Relation between elastic constants of an isotropic material; physical meaning and numerical value of Poisson"s ratio.

2. Computation of mechanical properties using rule of mixtures.

3. Computation of elasticity and stiffness matrix of an isotropic material.

4. Computation of elasticity and stiffness matrix of an orthotropic and transversaly isotropic material.

5. Computation of elasticity and stiffness matrix of an orthotropic and transversaly isotropic material - continuation.

6. Computation of altered mechanical properties at rotation of main material axes.

7. Computation of A,B,D matrices for symmetric and anti-symmetric layering setup.

8. Computation of A,B,D matrices for symmetric and anti-symmetric layering setup - continuation.

9. Computation of stress and strain distribution in laminate.

10. Computation of stress and strain distribution in laminate - continuation.

11. Computation of thermal stresses in laminate due to autoclave manufacturing.

12. Computation of thermal stresses in laminate due to autoclave manufacturing - continuation.

13. Estimation of laminate failure using maximum stress criterion.

14. Estimation of laminate failure using Tsai-Wu criterion and comparison with results by maximum stress criterion.

15. Application of first-ply and last-ply failure criteria - a critical review.

Compulsory literature:

1. Mechanics of Composite Materials, Jones, R.M., Taylor and Francis, 1999, p. 0-0

2. Stress Analysis of Fiber Reinforced Composite Materials, Hyer, M. W, McGraw - Hill, Boston, 1998, p. 0-0

3. Theory of Composites Design, Tsai, S. W., Think Composites, Dayton, 1993, p. 0-0

4. Composite Airframe Structures, Niu, M.C.Y., Conmilt Press, 1992, p. 0-0

5. Composite Materials in Aircraft Structures, Middleton, D. H., Longman Scientific & Technical, Harlow, 1990, p. 0-0

Recommended literature: