(1) Shear Locking Phenomenon
Fully integrated linear elements, such as 8-node solid elements, may suffer shear locking. False results may be produced with fully integrated 8-node solid elements.
(2) A Beam Example
Here is a simple beam example.
The theoretical solution of the beam problem is as follows.
Deflection = 4.281 mm
First mode = 284 Hz
Bending stress = 250 MPa
(3) Computed Deflection Using Fully Integrated 8-node Solid Elements
Deflection = 2.98 mm << 4.281 mm
(4) Shear Locking Explained
An ideal element should be able to bend like a classic beam.
However, fully integrated 8-node (linear) elements can't simulate bended edges under a moment because their deformed edges are straight (their shape function is linear). As a a result, they are too stiff; hence they produce shear locking.
