Single Span Beams
LAB APPARATUS
a. Simply-supported and Cantilever rectangular beams b. Weights c. Micrometer d. Ruler e. Dial Gauges
PROCEDURE
A. SIMPLY SUPPORTED BEAM
- Record the beam dimensions and calculate the area moment of inertia (I) using: I = bh3/12
- Calculate the maximum permissible loads for mid-span and quarter-span loading using Equation 1.3, where maximum allowable stress is 18,000 psi.
- Load the beam at the mid-span in 5 lb. increments, until the maximum load limit is reached. Record the deflection at the point of loading at each incremental load. Small divisions on the dial gage are 0.001 inch. One full revolution of the dial is 0.1 inch (100 small divisions).
- Repeat the above procedure at the quarter-span.
B. CANTILEVER BEAM
- Record the beam dimensions and calculate the area moment of inertia (I) using: I = bh3/12
- Calculate the safe loads at the mid-span and end of the cantilever beam using Equation Sigmamax= Mc/I (where M = moment at the section, I = moment of inertia), and a maximum allowable stress of 18,000 psi.
- Load the beam at the mid-span in 2 lb. increments, until the maximum load limit is reached. Record the deflection at the point of loading at each increment.
- Repeat the Repeat the above procedure at the free end of the beam. Care must be taken so that the displacement does not exceed the maximum travel of the dial gage.
Observation Table:
| Section Type | Types of loads | Length of member (L) | Breadth h(b) | Depth (d) | Weight (W) | At a distance from section 'X' | Bending Moment(Knm) | Shear Force(Kn) | Deflection (Delta) |
|---|---|---|---|---|---|---|---|---|---|
| Simply Supported | 1. U.D.L | ||||||||
| 2. Point Load | |||||||||
| Fixed | 1. U.D.L | ||||||||
| 2.Eccentric Point Load | |||||||||
| Cantiliver | 1. U.D.L | ||||||||
| 2.With an End Load | |||||||||
| 3.Concentrated Load | |||||||||
| Uniform Varying |