Designing with Glass

I.D. #

85008

Duration

1 Day

The understanding of brittle behavior is a prerequisite to efficient product design with glass, glass-ceramic, and ceramic-type materials. This short course will address the weakness of brittle materials and how it may be overcome; it will highlight the design principles for brittle materials and contrast them with those for ductile materials. The seminar will review the design tools, e.g. stress analysis, finite element analysis, photo-elastic methods, and experimental stress analysis, and illustrate how they may be applied to automotive, aircraft and consumer products. Formulas for mechanical stresses due to bending, twisting, and impact loads in beams, plates and tubes will be reviewed. Similarly, thermal stresses in above structures due to transient and steady state temperature changes will be estimated using simple equations. The role of fracture mechanics and failure analysis will be discussed from the point of view of product liability. Hands-on demonstration of glass failure and examination of fracture surface will be carried out in the classroom. Glass specimens with different surface abrasions will be fractured to illustrate the impact of flaw severity on long-term reliability. The fundamentals of glass behavior under mechanical and thermal loads will be emphasized. In particular, the strength and fracture properties of glass, glass-ceramics, and ceramics will be reviewed. Also discussed will be available commercial techniques for improving strength and fracture properties to make glass more attractive as a structural material. This will be followed by a review of design methodology and its application to glass and ceramic products in automotive, aircraft, space, consumer, and construction industries. The issue of product liability involving glass products and how to minimize it via product design will be addressed.

This course has been approved by the Accreditation Commission for Traffic Accident Reconstruction (ACTAR) for 3 Continuing Education Units (CEUs). Upon completion of this seminar, accredited reconstructionists should contact ACTAR, 800-809-3818, to request CEUs. As an ACTAR approved course, the fee for CEUs is reduced to $5.00.

Learning Objectives

By attending this seminar, you will be able to:

Explain why glass as a structural material behaves differently than metals or plastics and how such differences affect product design
Design glass components or structures that have adequate safety built into them to meet reliability requirements in the field
Examine fracture origin and estimate failure stress from mirror size
Improve design strength of glass articles by three times or more

Who Should Attend

This course is designed for mechanical, metallurgical and chemical engineers, materials scientists and those involved in handling, assembling, and failure analysis of glass products.

Prerequisites

Participants should have background or experience in handling, analyzing, examining or working with glass products.

Seminar Content

Silica Structure
- Silicon-oxygen bond
- Bond length and bond angles
- Si-O-Si tetrahedron
- Random network theory
- Water molecule
- Crack tip morphology
Silicate Glasses and Their Properties
- Mechanical properties -- Elastic modulus; Hardness; Strength; Toughness; Fatigue
Strength of Inorganic Glasses
- Brittle nature of glass
- Strength and weakness of glass
- Griffith flaw
- Types of strength
- Factors affecting strength
- Statistical nature of strength
- Strength of annealed glasses
- Strain tolerance of brittle materials
Thermal Tempering
- Tempering fundamentals
- High temperature properties -- Expansion and viscosity; Air quenching; Temporary tension; Beneficial stresses
Stress Relaxation
- Shear and volume relaxation
- Relaxation time
- Strain
- Annealing and softening points
- Stress release vs. viscosity
Fracture Process
- Fracture of glass
- Slow, medium and fast crack growth
- Fracture surface and energy
- Fracture mirror
- Failure stress
- Estimate of product life
Reliability of Glass Products
- Long term reliability
- Size effect
- Surface strength and variability
- Failure probability
- Threshold strength
- Fatigue life
Formulas for Bending and Thermal Stresses
- Bending of beams and plates
- Pressurization of tubes
- Twisting of tubes and rods
- Impact loading of plates
- Thermal stresses in plates and tubes
Automotive Glass
- Properties of float glass
- Air vs. tin side
- Surface flaws and their origin
- Fatigue degradation
- Windshield design and analysis
- Importance of edge quality
- Stone damage
- Delayed failure

Instructor(s):

Suresh T. Gulati

Dr. Suresh T. Gulati was a Research Fellow in the Science and Technology Division of Corning, Inc. where he specialized in the behavior of glass, glass-ceramics and ceramics subjected to mechanical and thermal loads, their fatigue and fracture properties, and their long-term reliability. Before joining Corning, he held positions with Cornell University, the University of Colorado, and Continental Can Company. Dr. Gulati has authored over 200 publications in the area of ceramic catalyst supports, fiber optics, liquid crystal display glasses, cathode ray tubes, space windows, automotive windshields, and stepper lenses made from high purity fused silica. He is a member of American Men and Women of Science and Who's Who in Technology Today. Dr. Gulati has a Ph.D. in applied mechanics from the University of Colorado, an M.S. in mechanical engineering from Illinois Tech., and a B.S. in mechanical engineering from the University of Bombay, India.

Testimonial

"Dr. Gulati explained a complex topic simply and clearly with direct industry relevance."
Martin Tune
Senior Engineer QMT
BMW MC LLC

"Excellent practical course to understand class. Glass nature and manufacturing processes confirmed with testing."
Brad Gauker
Senior Mechanical Engineer
Autoliv Electronics

Fees:

$725

SAE Members*:

$580 - $653

* The appropriate SAE Member discount will be applied through the Registration process. Discounts vary according to level of membership: Elite Member 20%; Premium Member 15%; Classic Member 10%

CEU