3. Kinematics of Deformation

Section C

Review to Section 3.12 to 3.17

 

  1. Time rate of change of element is given by the velocity gradient where the differential is with respect to the spatial coordinate system. This can be decomposed into

                                                 

where are the rate of deformation tensor and spin tensor respectively.

 

2.      Rate of deformation gives the rate of change of differential element  whereas the spin tensor gives the rate of rotation of  (see example 3.13.1).

 

3.      The dual vector of spin vector is  called the angular velocity. While spin causes only pure rotation, rate of deformation contributes to  in all non-eigen orientations..

4.      For any displacement field compatibility is satisfied, while for a specified strain fields need to invoke compatibility equations.

5.      Since compatibility conditions involves second derivatives of strain with respect to , if the strain field is a linear function of space then compatibility is automatically satisfied. (see equations 3.6.7 to 3.6.12, examples 3.16.1 to 3.16.3)

 

See solved problems on problem 3-22

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