Strength of Materials: Simple Stress

Simple Stress - is the intensity of force inside a solid material. The object is influenced that may lead to breakage or change on it's physical form. 

It is force per unit area, which is basically Pascal (Pa) Newton per square meter or Megapascal (MPa) which is Newton per square millimeter.

The stress is spread out in the entire cross-section of the item that reacts to the external force or load applied.

Different Kinds of Internal Forces:

• Axial Force - pull and or push action that is perpendicular to the cross section. Pull represents tensile force that tends to elongate the subjected member while Push represents compressive force that tends to shorten the subjected member, load usually denoted as P.
• Shear Force - total resistance to sliding the portion to one side of the exploratory section past the other in vertical or horizontal manner, usually denoted as Vx for horizontal shear force and Vy for vertical shear force.
• Torque - twisting the member either clockwise, counterclockwise or both, usually denoted as T.
• Bending Moments - resistance to bending the member about any axes, and are often denoted as M or Mx for moment about x-axis or My for moment about y-axis.

Studying material's strength is relevant to guarantee that the structure to be used will be safe against maximum internal forces that is produce by combining different kinds of loads. 

Engineering Mechanics: Introduction

Engineering Mechanics - is a field of science that deals with forces and its effect on rigid bodies. Engineering Mechanics are subdivided into two parts:

•  Statics - rigid bodies remains at rest while absorbing the effects and distributions of forces
• Force System - any arrangement where in two or more forces act on a body or on group of related bodies. 
• Three Major Divisions of Force System
• Concurrent - all forces pass through a common point
• Non-Concurrent - all of the lines of action of the forces in this system do not meet at one point
• Parallel - forces whose line of action are parallel, in same or opposite direction
• Applications - trusses, centroids, friction

• Dynamics - rigid bodies motion caused by the force applied to it, it deals with bodies in motion
• Kinematics - is the geometry of motion, the motion of a particle without considering the forces causing the motion
• Motion of Particles
• Translation - motion of rigid bodies where in a straight line pass through any two of its particles always remain to be parallel on its original position
• Rotation - motion of rigid bodies where in the particles move in circular paths with centers or axis of rotation on a fixed straight line
• Plane Motion - motion of rigid bodies where in all particles in the body remain at a constant distance form a fixed reference plane
• Kinetics - relates the force action on the body to its mass and acceleration
• Newton's Law of Motion
• a body at rest will remain to be at rest or in motion will remain in motion along a straight path unless acted upon by unbalanced force
• a particle acted upon by an unbalanced force system has an acceleration in line with and directly proportional to the resultant of the force system and inversely proportional to its mass
• in every action there is always an equal and opposite reaction
• D'Alembert's Principle
• the resultant of the external forces applied to a body rigid or non-rigid composed of a system of particles is equivalent to the vector summation of the effective forces acting on all particles