CH. 10: WOODEN BEAMS Flashcards
- Structural element that carries transverse loads
WOODEN BEAMS
-A piece of wood which is typically long and squared that can be used as a building material.
WOODEN BEAMS
TYPES OF BEAMS:
- SIMPLE BEAM
- CANTILEVER BEAM
- CONTINUOUS BEAM
- OVERHANGING BEAM
- FIXED END BEAM
SIMPLE BEAM TYPES:
a. JOIST
b. RAFTER
c. STRINGER
– directly support the floor boards.
JOIST
- wooden beam that supports the roofing in an inclined position.
RAFTER
- the ties are placed in bridge construction longitudinally.
STRINGER
- It is a beam with only one support, either left or right end, that carries loads or weights on the unsupported section.
CANTILEVER BEAM
- It is a beam that is supported or rests on two or more supports.
CONTINUOUS BEAM
- a beam that is almost similar to a simple beam where in it supported at two points however the loads are carried on the extended portion.
OVERHANGING BEAM
- a beam in which both ends supports are fixed.
FIXED END BEAM
- an extent of pressure due to the overlaid weight or due to the external forces acting on the wooden beam
BEAM LOADING
TYPES OF LOAD:
- DISTRIBUTION OF THE WEIGHT IMPOSED
- LENGTH OF TIME WHEN WEIGHT ARE IMPOSED
DISTRIBUTION OF THE WEIGHT IMPOSED:
A. CONCENTRATED LOAD
B. OVERHANGING LOAD
C. DISTRIBUTED LOAD
- It is a load resting at any point in the entire length of the beam.
CONCENTRATED LOAD
- It is a load resting on the extended portion of the beam.
OVERHANGING LOAD
- The weights are spread over the entire length.
DISTRIBUTED LOAD
DISTRIBUTED LOAD:
- UNIFORMLY DISTRIBUTED LOAD
- UNIFORMLY VARYING LOAD
LENGTH OF TIME WHEN WEIGHT ARE IMPOSED:
A. STATIC LOAD
B. PERMANENT LOAD (DEAD LOAD)
C. SHOCK LOAD (IMPACT LOAD)
D. ROLLING LOAD
- a load which gradually increases in magnitude upon a stationary beam.
STATIC LOAD
- It is a load where the forces act over a long period of time with no increase in magnitude (floor joist).
PERMANENT LOAD (DEAD LOAD)
- load that is suddenly applied (ex. Wooden bat that hits the ball).
SHOCK LOAD (IMPACT LOAD)
- load resulting from weights in motion or a load that is moving (ex. Weight imposed on a bridge by moving vehicles).
ROLLING LOAD
- refers to the reactions which the wooden beam has obtained because of applied forces.
MOMENT
- branch of mechanics that is concerned with the analysis of loads acting on physical systems (example is wood) that do not experience an acceleration, but rather, are in static equilibrium with their environment.
STATICS
THREE BASIC LAWS OF STATICS:
a. Σ𝑉=0 (sum of all vertical forces is equal to zero)
b. Σ𝐻=0 (sum of all horizontal forces is equal to zero)
c. Σ𝑀=0 (sum of all moments is equal to zero)
The sum of all vertical forces is equal to zero. The equation is : Σ𝑉=0
This equation states that all the forces acting up must equal all the forces acting down.
The sum of all horizontal forces is equal to zero. The equation is: Σ𝐻=0
This equation indicates that all the forces acting to the left must equal all the forces acting to the right.
The sum of all moments is equal to zero. The equation is: Σ𝑀=0
This equation involves rotation. It states that all the moments (or torques) trying to rotate an object in one direction must equal those trying to rotate it in the opposite direction.
