Study and Testing of Aluminum and steel Columns
Object: To obtain the information required for plotting the column strength curves for 2024-T4 or C1018 CD pin ended columns, and to obtain data on the effect of fixed end conditions on column strength.
References:
l. Wand Potts, pp95-97
2. mm pp 150-155; Steel Constriction, p 207-210
3. Alcoa Structural Handbook, pp102 ff
Procedure:
1. Obtain the ultimate load, by the stop of the dial method, for each of the columns supplied. Use the pin end fixtures. Deduct 0.125 inches from the length of the columns for each fixture used. Be careful not to deflect the column more than the minimum amount necessary toobtain the ultimate load.
2. Obtain the ultimate load for the longest column under conditions of both ends fixed and oneend fixed, one end pinned. Deduct L250 inches from the length of the column for each end fixture used.
Data Sheet:
1. Dimensions of columns
2. Material of columns
3. Type of end conditions
4. Ultimate load
Discussion Questions:
1. Show how actual strength compared with design strength by plotting the published column strength curve on the same sheet as the results.
2. How did the experimental value of K, the end condition factor, compare with published values? Let K equal unity for the pin-ended columns.
3. If there were no columns effect, what load would you expect the given test pieces to carry and why?
4. Discuss the effect on the results of not having the Wcolumns perfectly vertical. Show a proof by static’s for your conclusion.