Dear Friends
If it is given from the manufacturer that the elastic modulus in the fiber direction of a unidirectional CFRP material (E11) is X, How we can predict the elastic modulus of the material ( as an orthotropic material) in the other directions (E22 & E33) using (Rule of Mixture) or any other rule (if any)?
Regards
Orthotropic composites such as cellulose has multiple distinct yielding points. Thus, MoE (as gradient=change in tensile stress/change in tensile strain) on the stress-starin curve could be determined with reference to any one of these yield points.
Salam. You must do experiment for other two directions or get them using some theoretical methods like "strength of materials approach" and "elasticity approach" having properties of your composite constituents. See chap.3 of below book:
Mechanics of Composite Materials, Autar K. Kaw
Goodluck
Hello! You could use homogenization techniques with finite element analysis. In more details you could see it in my paper: https://www.researchgate.net/publication/226831563_Elastic_properties_of_composite_materials
Article Elastic properties of composite materials
What sort of orthotropic material are you looking at? what are the components of this orthotropic material?
Dear Akwasi Asamoah
The material is Carbon Fiber Reinforced Polymer.
Regards
If you do not know the tensile strength and the MOE of the CF and the P alone, you will have to do literature search or experiments to find them. Better to do both anyway. After that you can find tensile strength and the MOE in the three orthogonal (x, y, z) directions of the composite, both in one in which CF is highly oriented in P and another in which CF in randomly in P. Afterwards you can use standard models (equations) to work out the tensile strength and the MOE of composites. You may assume either uniform stress or uniform strain in the composites or work with both and compare. You can estimate other elastic constants from the stress-strain curve of tensile tests. Only ensure your plots are arising from repeated (multiple) tests of sound samples.
The following papers can be a good reference.
http://linkinghub.elsevier.com/retrieve/pii/S003238610601250X
Whilst there are theories that you could use to make a back of the envelope prediction, the general outcome of the World Wide Failure Exercise would suggest that most models break down at the extremes and so some base line mechanical testing is the only way forward.
With regard to back of the envelope predictions, don't forget that factors such as fibre architecture and processing route will affect the final properties of the laminate.
- Badges
- Science method