LESSON 1: (PART 1-4) Flashcards
is the branch of physics that considers the action of forces on bodies or fluids that are both at rest and in motion.
Mechanics
branch of engineering that applies the principles of mechanics to any design that must take into account the effect of forces.
Engineering Mechanics
The study of the internal effects of external forces applied to structural member. it includes stress, strain, deformation deflection, torsion, flexure, shear diagram, and moment diagram.
Strength of Materials or Mechanics of deformable bodies
FOUR DIFFERENT TYPES OF RESULTANT LOADINGS
- Normal Forces (F)
- Shear forces (V)
- torsional moment or torque (T)
- bending moment (M)
this force acts perpendicular to the area. it is developed whenever the external loads tend to push or pull on the two segments of the body
Normal Forces
it lies in the plane of the area and it develop when the external loads tend to cause the two segments of the body to slide over one another.
Shear force
this effect is developed when the external loads tent to twist one segment of the body with respect to the other about an axis perpendicular to the area.
Torsional moment or
Torque
it is cause by the external loads that tend to bend the body about an axis lying within the plane of the area.
Bending Moment
it is defined as the strength of a material per unit area of unit strength. it is the force on a member divided by area.
Simple stress
3 types of Simple stress
- Normal stress
- Shear stress
- Bearing stress
this stress is either tensile stress or compressive stress.
Normal stress
members subject to pure tension (or tensile forces) is under _________. while compression members (compressive force) are under ___________.
Tensile stress, Compressive stress
compressivoe force will tend to ________ the member. Tension force on the other hand will ten to ______________.
shorten and lengthen
Forces parallel to the area resisting the force cause _________.
Shearing stress
Shearing stress is also known as?
tangential stress
3 types of shear
- single shear (T= V/A)
- double shear (T= V/2A)
- punch (T= V/pi(dt))
It is the contact pressure between the separate bodies.
Bearing stress
formula of simple stress
simple stress= P/A
Formula of Shear stress?
T= P/A
Bearing stress formula
Sb= Pb/dt
one method of specifying the allowable load for a member is to use a number called the ___________.
Factor of Safety (F.S.)
it is a ratio of the failure load to the allowable load.
Factor of safety
formula of F.S.
F.S.= F(fail)/F(allow)
F.S. must be _____________ 1.0 in order to avoid the potential for failure.
greater than
A tank or pipe carrying a fluid or gas under a pressure is subjected to tensile forces, which resist bursting, developed across longitudinal and traverse sections.
Thin-walled pressure vessels
which more critical, tangential stress or longitudinal stress?
Tangential stress
what is the other term for tangential stress?
circumferential stress, hoop stress, and radial stress
Tangential stress formula
σt= pD/2t
what is the formula of tangential stress if there is an existing extend pressure (p0) and an internal pressure (pi)?
σt= ((pi-p0)D)/ 2t
formula of longitudinal stress
σL= pD/4t
