The Use of Structural Adhesives for Steel–Glass Facade Panels With Multi-Axial Stress–Strain Behavior—Experimental and Numerical Investigations

• Published in: Durability of Building and Construction Sealants and Adhesives, 5th Volume - (STP 1583) pp. 349 - 375
• Main Authors: Richter, C., Abeln, B., Geßler, A., Feldmann, M.
• Format: Book Chapter
• Language: English
• Published: 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 ASTM International 22.06.2015
• Subjects: Adhesives & Sealants; Adhesives, Coatings, Sealants & Inks; Bonded Joint Design; Civil Engineering; Civil Engineering & Construction Materials; Hyper-Elastic Adhesives; Non-Linear Finite Element Analysis; Steel–glass Connection
• ISBN: 0803176112; 9780803176119
• DOI: 10.1520/STP158320140117

In today's building architecture, the application of modern structural steel–glass facades is very popular. While the typical assembly of such steel–glass facades used to be with bolted point fixings, more and more facade panels are designed using multi-side bonded joints. These joints are either using L- or U-shaped edge frames, with two or three flank sides bonded. For applications of facade panels with multi-side bonding, mainly hyper-elastic adhesives are used. The work described in this paper was initiated by a German national research project and demonstrated the different multi-axial stress states in such multisided bonded joints. Both experimental testing as well as numerical calculations (with existing hyper-elastic material models) were carried out, leading to a thorough comparison of different numerical models. Large-scale component tests were performed with two different adhesives (a 2C silicone (SI) and a 1C polyurethane (PU)) on glass plates between 6 and 15 mm thick with both L- as well as U-shaped edge frames. All tests were performed at room temperature and standard climate conditions, not considering durability effects. These investigations are a fundamental step towards at last enabling the establishment of safe design procedures for such bonded joints, since today no reliable analytical methods are available for calculating such complex multi-axial stress states occurring within the bonded joint, while at the same time the existing finite element analyses (FEA) used in practice have often shown great deviations between experimental and numerical results, which could lead on the one hand to significant over-dimensioning, or on the other hand—more critically—to unexpected cases of damages.