I'm reading the Wikipedia article on virtual work, and there is the following quote:

Consider now the free body diagram of a deformable body, which is composed of an infinite number of differential cubes. Let's define two unrelated states for the body:

The $ {\displaystyle {\boldsymbol {\sigma }}} $ -State : This shows external surface forces T, body forces f, and internal stresses $ {\displaystyle {\boldsymbol {\sigma }}} $ in equilibrium.

The $ {\displaystyle {\boldsymbol {\epsilon }}}$ -State : This shows continuous displacements $ {\displaystyle \mathbf {u} ^{*}} $ and consistent strains $ {\displaystyle {\boldsymbol {\epsilon }}^{*}} $ .

The superscript * emphasizes that the two states are unrelated. Other than the above stated conditions, there is no need to specify if any of the states are real or virtual.

The two states defined above are said to be unrelated. What does it mean here? Surely stress and strain are related, as one causes the other?


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.