Materials and Processes in Manufacturing

E. Paul Degarmo, J T. Black, Ronald A. Kohser

Chapter 11 Nondestructive Evaluation - Brittle Coatings

Click the "Reset" button. The figure is the top view of a blue rectangular steel plate with constant thickness. The plate/part has a white brittle coating on it. The plate length is one and one-half times the plate height. Cracks will form in the brittle coating when the strain due to applied loading in the x-direction is equal to the coating fracture strain efc. The coating fracture strain is given in microstrain, µe; 1 µe = 1E-6.

Answer the following questions:
1. What is the direction of a crack in the brittle coating with respect to the direction of the applied stress?
2. For the given brittle coating fracture strain, what is the magnitude of uniaxial stress sx in the part when cracks first form?

The part material modulus of elasticity is = Ep = 205 GPa = 30E6 lb/in².
The coating material modulus of elasticity is = Ep = 1.5 GPa = 22E4 lb/in².

Tensile loading in the x direction can be applied to the plate by moving the slider.

Click "Reset" to initialize and the coating fracture strain will be set.
Increase load until cracks form.
Using the available data, answer the questions above.
The answer is available by clicking on the "Answers" button.

If you see this message rather than the simulation, your browser is not Java enabled.

The solution procedure is available HERE

© 2001 by Barney E. Klamecki. All rights reserved