glass panel in railing 1

[dzyn]

I am just now studying the yield line theory in my class (although class examples are for fixed boundary conditions not pinned) and came across the following problem for work. It seems that some-where, some-one should have solved this one before....or at the least there should be a quick reference.
A glass panel span between railing posts. It is point connected to the posts near the top and bottom.
The post spacing is 2'-6" the connections are 2' apart with 9" of glass cantilevering to the top and bottom.
Thus ~ panel size = 3'-6" x 2'-6"
The glass is 1/2" thick, tempered glass:
E=10.4x10^6 psi
Mod. of Rupture = 24,000 psi

The state building code says to design for 50 pound load over an area less than 1 sq. ft. And a safety factor of 4 is required for panels and their supports.

Any thought are appreciated.

 

[boo1]

Although some specifications are common to most glass handrail projects, such as ½-inch tempered glass, ½-inch spacing between panels, and 42-inch height requirements from the finished floor, there are many other variables to consider. These include following the proper building codes which can vary from state to state and, sometimes, even county to county. Model code regulations usually require either a 50-lb/ft uniform loading or a 200-lb concentrated load to the handrail at a distance of 42 inches above floor level.

REFERENCE STANDARDS:
Uniform Building Code 1997 - Section 509, Table 16-B "Guardrails"
BOCA National Building Code 1993 - Sections 1615.8.2 "Guard Designs and Construction" and 1615.8.2.1 "Infill Areas"
National Building Code of Canada 1995 - Section 4.1.10.1 "Loads on Guards"
Canadian Government Specifications Board (CGSB) CAN2-12.1 M90 - Tempered or Laminated Safety Glass
ANSI Z97.1 - 1984 (R1994) - Glazing Materials Used in Buildings, Safety Performance Specifications and Methods of Test

All stresses are to compare with major tension stresses. Experiments have shown that in-plane stresses lead earlier to failure than plate stresses due to bending, so for the maximum allowable stress for in-plane loads (shear panel loads) 90% of the values above should be taken.