Experimental Study

The experimental study considered the varied strength issues related to the adequate performance of the joist to include clinching requirements for the closed chord, shear strength of the edge stiffened open web, and the flexure capacity of the closed chords.

Fig. 3. ced web opening.

Fig. 4. figure.

Using a simulated uniform loading test rig that enabled load to be applied by pneumatic cylinders spaced 12 inches on center, the joists were tested to failure (Figure 4). The experimental studies were performed in the structural engineering laboratory in the Department of Civil Engineering at the University of Missouri-Rolla.

Table 1. Mechanical properties.

Sheet

Yield

Tensile

Elongation

thickness

strength

strength

%

(in)

(ksi)

(ksi)

0.046

51.4

61.5

31.5

0.035

51.3

60.8

33.7

Table 2. Clinch connection test results.

Test

No.

Clinch

Type

Failure Load (lb/ft)

1

“A”

129

2

“R”

130

3

“A” & screws

149

4

“R” & screws

377