How to Calculate the Carrying Capacity of Glass

1. Glass bearing state

Doors, windows, curtain wall under the action of wind pressure in two states:First, four-sided support, apply to a frame doors and windows, walls.Second, two pairs of side support, suitable for glass doors.

2. The glass is subjected to wind load calculations

A) from the JGJ113 found in the three groups of formulas

When four sides of the support, when t ≤ 6mm, Wk = 0.2α majorityWhen t & gt; 6 mm, Wk = α (0.2t1.6 + 0.8) / Amax minorityTwo pairs of side support, Wk = 0.142αt / L glass doorWhere, Wk - wind load standard value kPaAmax - the largest area of ​​glass ㎡L - allowable span of glass mT - glass thickness mmΑ - adjustment factorGlass adjustment factorType of glass Ordinary semi - toughened steel laminated interlayer hollow filament embossing fireproofingAnd the adjustment coefficient is 1.01.62.0 to 3.00.81.50.50.63.0 to 4.5

B) Example calculation

Example 1, the use of outside the steel, the float within the hollow glass, 4 + A +5 size of the steel 1200 × 1800, the glass carrying capacity?The formula: Wk = 0.2 ?.Calculation and value: Wk = 0.2 × 1.5 × 41.8 / 1.2 × 1.8 = 1.68kPa.Analysis: ① steel sheet and float combination, according to slice favorable, otherwise unfavorable, cost is also high;② assume that the same two-piece, for the steel outside, within the float, not for the account;③ JGJ102 provides for the outside of steel, according to the lateral steel calculation.Example 2, the use of outer fire glass thickness 5mm, the inner layer of glass 4mm thick laminated glass, the size of 1200 × 1800, to find the glass carrying capacity?The formula: Wk = α (0.2t1.6 + 0.8) / AmaxCalculation and value: Wk = 0.8 (0.2 × 91.6 + 0.8) /1.2 × 1.8 = 2.78kPaAnalysis: ① at this time carrying capacity, but the main role is to fire, high cost;② tempered glass and monolithic fire resistance of glass pressure coefficient should be determined by the test.Example 3, the use of 15mm tempered glass, the size of 800 × 2000mm door, ask the glass carrying capacity?The formula: Wk = 0.142? T / LCalculation and value: Wk = 0.142 × 2 × 15 / 2.0Analysis: ① glass doors require strict, and the thickness of large;②L the most negative for the long side, short side was 1.94kPa;③ glass damage is mainly tension damage, not pressure damage, so bending is the main contradiction.

3. The Problems in Calculation

A) JGJ113-2003 and 97 are the same calculation formula, but the parameters slightly change.Example: tempered glass from the original 1.5 to 3.0 to 2.0 to 3.0 and increase the fire glass adjustment factor.B) Curtain wall with glass still JGJ102 - × × × × the provisions of the two are different, not mixed.C) tempered glass and float glass composed of insulating glass, and the thickness of the two different, how to deal with.The outer layer of steel + inner float, when the two equal α 1.5; outside the thin inner thickness, take the thin, the problem is not big; thin thickness when the outside, it is not easy to use.D) laminated glass When the use of conditions more than 70 ℃, α adjustment coefficient from 0.8 to 0.6, the South should pay attention to use.E) tempered glass, fire-resistant glass adjustment factor to a range, how to value, preferably provided by the manufacturer, or take a small value is beneficial, including the combination of steel and fire to determine the test included.F) tempered glass, different parts, the best glass manufacturers to provide, and to bear financial responsibility.Analysis: ①ANSI is the glass factory to provide parameter values, and to ensure quality;② tempered glass has the problem of self-violence, about 8% 0 abroad, abroad than this value;③ tempered glass assembly problems, deformation of the problem, the glass flatness of 2% 0, which take the lower limit favorable.G) The problem of glass calculation, as well as the following items, is not within the scope of this, but should be noted.Such as glass disturbance, glass thermal stress, glass gravity, glass gap, glass thermal performance, underwater glass.