ABOUT THE COURSE: The course introduces to the various engineering aspects of polymers and composites. It discusses the unique mechanical properties that these materials offer over metals and how they are related to the structure of the materials. It teaches the mechanics of these materials that include the viscoelastic analysis of polymers and classical lamination theory for composite laminates. It also describes the failure behavior and design aspects of these materials. The course prepares a student to work on research and engineering problems related to polymers and composites.INTENDED AUDIENCE: UGs and PGs from Mechanical, Materials, Aerospace, Automotive, Civil, and other related engineering branches. Working professionals associated with polymers and composites.PREREQUISITES: UG courses in Engineering Mechanics and Solid MechanicsINDUSTRY SUPPORT: All industries working on polymers and composites such as aerospace, automotive, marine, railway, sports, infrastructure, and energy.
Mechanical Behavior of Polymers and Composites
Indian Institute of Technology Delhi and NPTEL via Swayam
Overview
Syllabus
Week 1:INTRODUCTION TO POLYMERS
- Common polymers and applications
- Bonding and polymerization
- Thermoplastics, thermosets, elastomers and natural polymers
- Molecular packing (crystalline and amorphous), glass transition temperature
- Viscoelastic and rubbery behavior; Cold drawing and crazing
- Creep and relaxion tests
- Linearity – isochronous stress strain response
- Kelvin, Maxwell, 3 parameter and 4 parameter models
- Generalized Kelvin and Maxwell models
- Boltzmann superposition principle
- Alfred’s correspondence principle
- Stress analysis of bars and beams
- Time temperature superposition principle, WLF equation
- Dynamic mechanical analysis, storage and loss modulus
- Plastic design considerations and practices
- What are composites and how they are different from other materials
- Advantages and applications; Materials and types of composites
- Aspects involved with composite structures
- Generalised Hooke’s law for anisotropic materials
- Stress-strain and material symmetry
- Engineering constants for orthotropic materials
- 2D stress strain relations of lamina
- Failure criteria of lamina
- Hygrothermal stress in lamina
- Estimation of lamina properties from properties of constituent materials
- Classical lamination theory
- Stiffnesses of commonly used stacking sequences
- Hygrothermal stresses in laminate
- Failure strength of laminates
- Design principles and considerations in composite structures
- Composite sandwich structures
- Testing, joining and repair of composites
Taught by
Prof. Naresh Varma Datla
