Dynamic properties of resilient studs used in soundproof multilayer constructions – Measurement method and database

The sound insulation of mechanically coupled multilayered constructions, such as most lightweight floors and walls, strongly depends on the resiliency of mechanical line connections installed between the layers. Typical examples of line connections (later: studs) are vertical or horizontal wall studs (a.k.a. bars, posts, or channels), horizontal floor or ceiling joists, and the frame around them. The sound insulation of such a construction improves with reduced dynamic stiffness per unit length, K', of the stud. There is no standardized method of measuring the K' of resilient studs. The purpose of this work was to introduce the experimental test method developed for the dynamic testing of resilient studs. The apparatus contains a broadband vibration exciter, two planar load masses hanging from heavy ceiling slab, vibration and force transducers, and a two-channel real-time analyzer. The stud sample is placed between the load masses. The method has been applied for 30 geometrically different resilient studs. The thickness of studs varied from 17 to 125 mm. The results include a database showing most typical stud profiles and their K' values and loss factor values. The measured range of K' was 0.08–6.91 MN/m2. The measured range of loss factor was 0.007–0.029. The work has two practical implications. First, the method could be considered in standardization committees. Second, the database can be applied in the prediction of sound insulation of multilayered constructions in cases when the K' value of stud is not available nor measurable.