Full-Scale Test Procedure

Test assembly 1 consisted of a curtain-wall frame anchored to a wood test frame at each corner (see Fig. 3). The wood frame was rigidly anchored and sealed to the test wall with the exterior lite of glazing facing the test wall. All gaps between the curtain-wall unit and wood test frame were also sealed. It was sub­jected to initial pressurization of four positive and four negative cycles of 10 s each at 100 lbf/ft2 (4788 Pa) in general accordance with ASTM E330-02 [10] to ensure that the glass could attain design pressures prior to cold-bending. The upper-right anchor was removed and the top corner of the unit was pulled 2 in. (50 mm) out of plane away from the test wall. The anchor was reinstalled, and one 10-s cycle was run for the positive and the negative pressures. This proce­dure of displacement followed by pressurization was repeated in 2-in. (50-mm)

0.8

■0.8

Strain

FIG. 2—Stress-strain relationship of silicone at 22° C.

Copyright by ASTM Int’l (all rights reserved); Tue May 6 12:07:08 EDT 2014 Downloaded/printed by

Rochester Institute Of Technology pursuant to License Agreement. No further reproductions authorized.

Stress at 10% strain (MPa)

0.55

0.46

0.57

0.58

0.65

0.56

0.07

Stress at 10 % strain

(psi)

79.1

66.2 82.9 84.8 94.6 81.5 10.3

Stress at 5 % strain (MPa)

0.29

0.09

0.37

0.49

0.43

0.33

0.15

Stress at 5 % strain (psi)

42.1

13.3

53.2 71.6 61.9

48.4

22.4

Stress at 2.5 % strain (MPa)

0.02

0.06

0.10

0.24

0.26

0.14

0.11

Stress at 2.5 % strain (psi)

2.3

8.9

14.1

34.7

37.8 19.6

15.8

.Я cd ^

a

(N h OO h h M oo ю oo oo (N (N гн

1Л ‘С ті rH r<i d ri Ю Ю G Ю

Peak

stress

(MPa)

1.42

1.49

1.49 1.53 1.51

1.49 0.04

M $ C7

t t ^ ^ ^ ^ ^

Cd 0) СЛ <0 U Cl, CL +-1

I-4 <S)

to d d < oo in d о 04 N N N n (S n

Thickness

(in.)

0.375

0.375

0.375

0.375

0.375

Length

(in.)

N N N П (S

Specimen #

1

Я

cd

гн Г4 ГО ’t Ю ^ (/)

FIG. 3—120 x 60 x 1 in3. (1.5 x 3.0 m2 x 25 mm). Full-scale test assembly 1.

increments until a total displacement of 12 in. (300 mm) was reached. After pres­surization at a displacement of 12 in (300 mm), the unit was displaced till breakage at 15 in. (380 mm). Linear and rosette strain gauges provided strain information at key locations, and linear variable displacement transducers (LVDTs) were attached to the glass in the corners to provide accurate displacement data. Data from these gauges was recorded for each displacement increment and during all load cycles. Figure 4 shows the locations of these gauges on assembly 1.

Assembly 2 was installed in a partial-wood test frame and anchored at three locations, leaving the top right corner free (Fig. 5). The partial frame allowed access to the side of the glazing where six dial indicators were mounted to the outer pane of glass (Fig. 6) to monitor the edge-seal strains as the unit was dis­placed. Consequently, the frame was unable to be sealed and no pressure was applied to assembly 2. The free corner was displaced in 2-in. (50-mm) incre­ments until a total displacement of 12 in. (300 mm) was achieved. Dial indicator and linear strain (Fig. 7) readings were recorded at each 2-in. (50-mm) incre­ment and LVDTs were again used to measure glass bending.

Assembly 3 followed the same installation as assembly 1. For this assembly, the top right corner was displaced to 10 in. (250 mm) and secured. Eight 10-s, 100 lbf/ft2 (4788 Pa) test loads were applied in accordance to ASTM E330-02 [10], alternating between positive and negative directions. Linear and rosette strain gauges and LVDTs were applied to this assembly as shown in Fig. 8. During the time of testing, the authors decided that design cold bend would be 8 in. (200 mm) and the 10 in. (250 mm) displacement would correspond to 125 % of the design dis­placement of assembly 1. This was done to determine if repeated loading beyond the 100 % cold-bend design would result in glass breakage of this single assembly.

Copyright by ASTM Int’l (all rights reserved); Tue May 6 12:07:08 EDT 2014

Downloaded/printed by

Rochester Institute Of Technology pursuant to License Agreement. No further reproductions authorized.