SLS Glass Deflection Review
VitraLab separates serviceability deflection from ULS stress so glass movement can be reviewed against the selected limit and project criteria. For engineers comparing glass deflection software or spreadsheet workflows, VitraLab provides a web-based tool for reviewing SLS deflection inputs, limits, and output warnings.
Span, Thickness, and Support Type
Deflection is sensitive to pane span, glass thickness, aspect ratio, and support condition. Four-edge, two-edge, and one-edge support models can produce very different results.
Wind Load and Structural Glazing
Facade glass and curtain wall glazing are often governed by wind suction or pressure. Deflection should be checked together with stress, support details, and framing assumptions.
Laminated Glass Deflection
Laminated glass deflection depends on glass ply thickness, interlayer assumptions, load duration, and the selected design workflow. The build-up should match the project specification.
Vertical and Horizontal Glazing
Vertical glazing, rooflights, canopies, balustrades, and horizontal glass can have different serviceability expectations, drainage issues, and visual movement limits.
Result Review
The output should be checked against project specifications, support stiffness, fixing details, local requirements, and engineering judgement before final design use.
Example Structural Glass Deflection And Stress Checks
Example VitraLab outputs for laminated glass, DGU glass, and balustrade-style support conditions.
Frequently Asked Questions
What is glass deflection?
Glass deflection is the movement of a pane under service load. It is usually reviewed separately from stress because a pane can be strong enough but still too flexible for the project.
What affects glass deflection most?
Pane span, thickness, support condition, load magnitude, aspect ratio, laminated glass assumptions, and selected serviceability limit all affect deflection.
Is SLS deflection the same as ULS stress?
No. SLS deflection reviews serviceability movement, while ULS stress reviews strength under design load combinations.
Can wind load govern glass deflection?
Yes. For facade and structural glazing, wind pressure or suction can control the deflection check even when stress utilization is acceptable.