The image to left is a panel under load. Deflection depicted is exaggerated, actual deflection will be less. The image to the right is a panel under no load in a stationary position.
The following criteria are considered industry standard or above such and are observed in the design process.
3-side support panels Deflection Standards
Most panel fabricators will design their 3-side support transparencies to an industry maximum deflection standard of L/400. However, there is an issue to this standard, thus below we shall explore an alternative solution and evaluate the issues with this standard.
Panel A) 3-side support 100”L x 40”H
Panel B) 3-side support 200”L x 40”H
As we can see both panels are of equal height. However, based upon the industry standard design criteria of L/400, panel B would be able to deflect twice that of panel A. Thus the thickness of transparency B could be thinner then transparency A. Also based upon this, criteria a panel could theoretically deflect an infinite amount.
A more appropriate standard that Innovative Acrylics observes is <= H/200 OR <=L/400 whichever is less. Thus panel A and panel B would be able to deflect the same amount.
Standard cantilever embedment depth
Standard cantilever embedment depth with reduced water depth.
In this depiction the embedment depth is reduced thus a thicker panel is required to reduce deflection.
4-side Support Panels Deflection Standards
Structural loading panels with 4 side supported edges: Initial predicted deflection <= 1/300 the length of the shortest edge.
This is a depiction of a 4 side support panel stationary with no loading.
Reducing deflection beyond industry standards
All Innovative Acrylics transparencies are designed to strict standards for deflection and stress criteria, thus reducing deflection beyond these criteria is solely a cosmetic undertaking. There are several options to achieve this:
- Increase the thickness of the transparency.
- Reduce the panel size.
- Reduce the water depth.
- Increase rebate bearing face support.
Design Stress for 3 side and 4 side support panels
- The minimum tension and flexure design safety factor for panels shall be 11.2. Per ASME-PVHO-1
- The minimum compression design safety factor for panels shall be 8. Per ASME-PVHO-1
Design and Engineering Process
With just a concept, the design and engineering process is imperative to ensure the proper thickness transparency is selected. Engineering is accomplished by first completing an intake analysis to understand the specifics of a project. Next the engineer will produce a computer-generated model of the transparency. The engineer will then apply a simulated load in an FEA program to accurately predict the intended application. After all variables are accounted for the simulation is run and evaluated for its accuracy. Finally production drawings are produced and submitted for client approval and fabrication.
3 side support panel with constrained edges. This report shows directional loading pattern.
Report showing predicted loading and deflections.