Sound Barrier Acrylic Deflection Limit

[tristrium]

I have been provided a design for acrylic panels for a sound barrier by the manufacturer. They have designed to a deflection limit of span/20 or 75mm which they have claimed is standard practise in the USA but can't produce any reference documents. In Australia AS5100.2 cl25.3.8 stipulates span/60.

Does anyone have any reference documents that would support a deflection limit of 75mm or span/20? The panel size is 2.5m x 1.5m.

 

[bugbus]

Span/20 seems like it would start to tug on the fasteners or pull out of whatever is holding it in place. I'm sure the panel itself is fine for that deflection.

 

[SWComposites]

75mm (~3 inch) deflection seems like a LOT for that size panel.

 

[tristrium]

Thanks. I agree that it seems large. However I have found the specification below from DOT New York which references 3 inches. I cant find it in any standards however.

The maximum elastic deflection of the transparent acrylic noise barrier panel, under the design
wind load shall be less than 3 in (76 mm). When a load factor of 1.5 is applied to the design wind
load:
 The panel shall not show any symptoms of failure such as buckling or cracks.
 The sheet shall not become detached from its supports or fittings.