Numerical analysis on the natural vibration frequencies of insulating glass units: key trends and sensitivity to geometrical, mechanical, cavity features

Insulated glass units (IGUs) represent composite systems that are extensively utilised in buildings, due to their superior thermal and acoustic potentials. From a structural standpoint, an IGU exhibits higher performances in comparison to a single monolithic or laminated glass pane, thanks to the collaboration of its components. Besides, the mechanical analysis of IGUs is rather challenging due to the influence of multiple parameters, including basic geometrical features (i.e., thickness and size of the constituent glass panes), as well as properties of edge connections and mechanical boundary conditions. Additionally, fluid-structure interaction phenomena due to the presence of the gas-filled cavity and its features (i.e., thickness and type of infill) should be properly considered. These influencing parameters could be even more critical for in-service IGUs, where long-term phenomena or unfavourable operational conditions could lead to possible loss of functionality. For maintenance optimization, it is thus important to find key performance indicators that could be used for structural assessment and monitoring purposes. This paper thoroughly investigates the vibration response of selected IGUs by means of more than 100 modal analyses carried out in ABAQUS, pointing out the effect of such a multitude of factors on the vibration frequencies and shapes. The vibration frequencies implicitly reflect a possible change in terms of mechanical performance of the IGU and can consequently represent a preliminary but meaningful diagnostic parameter. The parametric analysis highlights some important quantitative and qualitative variations in terms of key vibration parameters and can thus suggest the elaboration of an efficient monitoring strategy for in-service IGUs.