Testing of Structural Glass Elements: Background and Methods in the Structural Glass Design Manual

Background and Methods in the Structural Glass Design Manual

Abstract

Testing forms an important part of designing structural glass systems. Calculation generally only predicts failure of the mechanisms that are checked for, so rely on the experience and judgement of the designing engineer. However, glass systems lack ductility and are intolerant to incorrect assumptions, so validation testing, even when calculations are well prepared, performs an important role. Design standards with equations for the applicable limit states are available for most structural materials and are the most common approach. “Rational analysis” based on published papers and engineering fundamentals is another approach where there are gaps in the local codes and standards. Another method is “design by testing” which can be a great approach to optimize the design and calibrate the limit state if used correctly. However, as our standards have been advanced to cover more of the limit states with empirical formulas, practicing engineers have had less exposure to “design by testing” and we have seen inconsistencies in the application of this method in practice such as consideration of “validation by testing” to be equivalent to full justification. This paper is intended to walk through the “design by testing” method, highlighting on appropriate references, statistical analysis of the results and the appropriate reliability and safety factors to align with the standardized reliability objectives. The paper will also highlight the difference between “design by testing” and “validation by testing” and discuss the objectives of each approach, how they can be employed in practice, and how they are addressed within the Structural Glass Design Manual.