Introduction To Solid Mechanics

Solid Mechanics OR Mechanics of Materials OR Strength of Materials:

It is the study of mechanics of body i.e. forces and their effects on deformable solids under different loading conditions.

Deformable Body Mechanics:

It is the study of non-rigid solid structures which deform under load.

• Deformation/Distortion ⇾ change of shape and size OR have some relative displacement or rotation of particles. It happens when we apply combined load.
• Rigid Body Motion ⇾ Translation or rotation of particles but having constant distance between particles.
• Since deformation occur at particular load. Below this load, every body is considered as rigid body.

Types of Load:

1. Point Load  ⇾  Load apply on a single point i.e. concentrated load.
2. Uniformly Distributed Load (UDL)  ⇾  Load remains uniform throughout an area of element like beam.
3. Varying Distributed Load (VDL)  ⇾  Load varies with length with constant rate.
4. Moment  ⇾  It measures the tendency of a body to rotate.

Distribution Of Forces:

1. Normal Force (N)  ⇾  Force applied perpendicular to the area and is developed when external loads tend to push or pull the body.
2. Shear Force (V)  ⇾  Force applied parallel to the area and is developed when external loads tend to slide.
3. Torsional Moment OR Torque (T)  ⇾  External Force tends to twist a body.
4. Bending Moment (M)  ⇾  External loads that tend to bend due to transverse loading.

Important Terms:

• Transverse Loading  ⇾  Load applied perpendicular to the axis of body.
• Supports  ⇾  Elements used to restrict motion of member.
• Reactions  ⇾  These are forces produced due to those restrictions.
• Degree of Freedom (DOF)  ⇾  Number of independent coordinates in which an object can move.
• Equilibrium of Forces  ⇾  It prevents body from translating and having accelerated motion.
• Equilibrium of Moment  ⇾  It prevents body from rotating.

Procedure of Analysis:

Resultant internal force are required and can be found by the Method of Sections (require determinations of support reactions and resultant internal loads using equilibrium equations). 

Steps are as follows:

1. Draw free-body diagrams using all external distributed loadings, couple moments, torques, forces at exact locations. 
2. Determination of support reactions.
3.  Determination of resultant internal force and moments using equilibrium equations.

References:

• Material from Class Lectures + Book named Engineering Mechanics of Materials by R.C. Hibbeler (10th Edition) + my knowledge. 
• Pics and GIF from Google Images.  
• Videos from YouTube.