Mechanics Composites Flashcards
What does ‘In-Situ’ mean in the context of laminate consolidation?
‘In-situ’ means ‘on-site’ or ‘in place.’
What is in-situ laminate consolidation in AFP?
The process of bonding and consolidating composite layers during deposition, without needing additional post-processing like autoclaving or hot pressing.
What is laminate consolidation?
The process of removing voids (porosity) and bonding composite layers together to achieve a high-quality, structurally sound final part.
What are the benefits of proper laminate consolidation?
- Good interlayer bonding
- Minimal voids
- Optimal mechanical properties
What are key factors affecting in-situ consolidation?
- Prepreg Tape Quality
- Processing Temperature
- Compaction Pressure
- Deposition Speed
Why is in-situ consolidation important?
- Eliminates the need for autoclaves
- Improves manufacturing efficiency
- Enables large-scale, rapid manufacturing
What is an autoclave?
A high-pressure, high-temperature chamber used for curing composite materials and sterilization.
What role do autoclaves play in composite manufacturing?
They ensure high-quality, void-free laminates with excellent mechanical properties.
What are the main steps in the autoclave curing process?
- Layup & Bagging
- Placement in Autoclave
- Heating & Pressurization
- Curing & Cooling
What are the advantages of autoclave processing?
- Improves laminate quality
- Ensures uniform curing
- Achieves high mechanical performance
What are the disadvantages of autoclave processing?
- High cost
- Slow processing time
- Limited scalability
What are alternatives to autoclave curing?
- Out-of-Autoclave (OoA) Processing
- Automated Tape Placement (ATP) with In-Situ Consolidation
- Resin Transfer Molding (RTM)
What is a quasi-isotropic laminate?
A composite laminate configuration that mimics isotropic material behavior in the plane of the laminate.
What are the key features of quasi-isotropic laminates?
- Balanced stiffness & strength in multiple directions
- Commonly used in aerospace and automotive
- Typically made using at least 3 or 4 different fiber orientations
How is a quasi-isotropic laminate achieved?
- Using multiple fiber orientations
- Through random fiber distribution
What is the difference between quasi-isotropic and isotropic materials?
- Quasi-Isotropic: Controlled fiber orientation, different out-of-plane properties
- Isotropic: Random orientation, uniform in all directions
What are applications of quasi-isotropic laminates?
- Aerospace: Aircraft fuselage, wings
- Automotive: Carbon fiber body panels
- Sports Equipment: Tennis rackets, bicycle frames
Is a quasi-isotropic laminate truly isotropic?
No, it approximates isotropic behavior in-plane but is anisotropic in the through-thickness direction.
What is an isotropic material?
A material with the same mechanical, thermal, and physical properties in all directions.
What are examples of isotropic materials?
- Metals: Steel, aluminum
- Glasses: Window glass
- Some Polymers
- Ceramics
What is the difference between isotropic and anisotropic materials?
- Isotropic: Same in all directions
- Anisotropic: Different in different directions
What is the key distinction between isotropic and quasi-isotropic materials?
- Isotropic: Uniform in all directions
- Quasi-Isotropic: Approximate isotropy only in-plane
