Types of stress

Bending is a combination of both tension and compression
Tension occurs on the outer (convex) surface, compression on the inner (concave).

By careful selection of materials used in beams, the strength of the beam can be controlled. That is how hockey sticks, skateboards and snow-boards can be designed with specific handling characteristics.
 


Flex in skis (and snowboards) affects handling characteristics.


Tuning (tightening)  guitar strings causes the neck to bend.