Stress Strain Behavior Determination Ceramics

1 2 tensor notation for stress 5 1 3 stress in rotated coordinate system 8 1 4 principal stress 11 1 4 1 principal stresses in three dimensions 15 1 5 stress invariants 16 1 6 stress deviator 16 1 7 strain 17 1 8 true stress and true strain 20 1 8 1 true strain 21 1 8 2 true stress 22 problems 23 2 types of mechanical behavior 27 2 1.

Stress strain behavior determination ceramics.

1 2 typical stress strain curve of a ductile metal2 the material initially behaves in a linear elastic manner. Stress and strain are linearly related and. It s also called modulus of rupture fracture strength or the bend strength. Stress strain behavior 6 3 a specimen of aluminum having a rectangular cross section 10 mm 12 7 mm 0 4 in.

In engineering and materials science a stress strain curve for a material gives the relationship between stress and strain it is obtained by gradually applying load to a test coupon and measuring the deformation from which the stress and strain can be determined see tensile testing these curves reveal many of the properties of a material such as the young s modulus the yield strength. The stress at fracture under the bending tests. For brittle ceramics a three point bending apparatus shown in the figure below is used determine the stress strain behavior and the measurement results are used to calculate an equivalent modulus of elasticity. With the sample geometry a stress strain curve can then be generated from the recorded load and displacement.

3 point bending tests 3 2 2 3 r f l bd f l f fs f fs. The nonlinear stress strain behavior size dependent strength fracture mode transition and other phenomena are not adequately explained by the classical concepts of the mechanical behavior of materials and mechanics of fracture 28 30. Enquiry into such aspects of the behavior of materials is essential in assessing the material properties. This reversible behavior often shows a linear relation between stress and.

A typical stress strain profile for a ductile metal resembles the following. Calculate the resulting strain. 0 5 in is pulled in tension with 35 500 n 8000 lb f force producing only elastic deformation. Stress and strain.

These are size independent measures of load and displacement respectively. Stress strain behavior of ceramics flexural strength.