4MM00 - Composite and light-weight materials: design and analysis
Content
The use of light-weight materials and carbon-fiber reinforced composites in particular is essential in the design of energy efficient vehicles such as cars and airplanes. In this course we will study the mechanical behavior of fiber-reinforced composite materials and light-weight design principles, such as stringer stiffened shell structures.
The composite materials are studied on various length scales, starting from micro-scale, where the individual constituents (fibers and matrix) are visible, via the meso-scale (individual layers) to the macro-scale where geometric instabilities (buckling) are crucial. In order to fully understand the interaction of failure mechanisms on all levels of observation, the use of homogenization techniques is key and will be addressed in this course as well.
Topics:
Composite Materials: constituents, manufacturing and experiments
- General overview of different materials/constituents.
- Manufacturing techniques.
- Long fiber / short fiber composites.
- Homogenization techniques to obtain laminate properties from individual constituents.
- Rule of mixtures.
- Eshelby solution based methods (Mori-Tanaka).
Elastic behavior of multi-directional laminates (analytical techniques)
- Classical Laminate theory.
- Laminate stiffnesses and compliances.
- Special types of laminates (symmetric, balanced, quasi-isotropic).
- Hygrothermal effects (effects of temperature and moisture).
Failure analysis of multi-directional Laminates (analytical)
- Stress analysis.
- Micro-mechanical failure mechanisms.
- Progressive and ultimate failure.
- Buckling.
Computational techniques
- Element technology (shell elements, solid-like shells, interface elements).
- Numerical analysis of buckling.
- Failure criteria.
- Computational homogenization.
- Constitutive models (damage models).
Cohesive zone models / delamination.
Design methodology for composite structures
- Requirements / safety factors.
- Design methodology.
- Best practices.
Objectives
The students are able to predict the mechanical behaviour of composite materials using both analytical and numerical models. They are able to apply these models in the design of lightweight structures.