6834 Lecture Notes - Lecture 8: Military Orders, Awards And Decorations, Ankle, Shear Stress
21 Jun 2018
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BIOMECHANICS 1/G MECHANICS OF BIOLOGICAL SYSTEMS 1
STRESSES (Force / Load)
Force and load is referred to as stress to enable more ready comparisons with other
materials. The impact of a force will be different depending on the area over which
the force is acting. The consideration of force about the area it acts is termed stress
MECHANICAL STRESS
Is the internal force divided by the cross sectional area of the surface with which it
acts:
Stress = Force / Area
The applied loads or forces to a material can be gradual (such as when lifting a
barbell) or impulsive (such as a heel strike impact in running). The applied load can
also either be applied once (acute loading) or applied several times (repetitive
loading)
When an applied load (stress) acts on a material it causes the material to deform in
different ways. The nature of the deformation can be described and related to its
function.
COMPRESSION
Compressive force, or compression, can be thought of as force that pushes the
object together. The object undergoing a compressive load will shorten in the
direction of the load.
Self-Task – Press your 2 palms together – this is an example of applying
compressive forces to your palms.
In human motion, the weight of the body acts as a compressive force on the bones
that support it. When the trunk is erect, each vertebra in the spinal column must
support the weight of that portion of the body above it. This is why in back injuries in
athletes often axial loading of the skeleton is ceased particularly moves such as
Back squats.
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Document Summary
Force and load is referred to as stress to enable more ready comparisons with other materials. The impact of a force will be different depending on the area over which the force is acting. The consideration of force about the area it acts is termed stress. Is the internal force divided by the cross sectional area of the surface with which it acts: The applied loads or forces to a material can be gradual (such as when lifting a barbell) or impulsive (such as a heel strike impact in running). The applied load can also either be applied once (acute loading) or applied several times (repetitive loading) When an applied load (stress) acts on a material it causes the material to deform in different ways. The nature of the deformation can be described and related to its function. Compressive force, or compression, can be thought of as force that pushes the object together.
