Civil Engineering Reference
In-Depth Information
Chapter 4
The Development of Biaxial Testing
Devices and Procedures for Architectural
Fabrics
Abstract This chapter analyses the technical requirements for the development of
biaxial testing devices and procedures for architectural fabrics. The description
includes the overall shape and stiffness of the frame, the sample shape and
dimensions, the clamping system, the stroke of the actuators, the loading pro
le, the
transducers for force, strain and displacement, the temperature and humidity con-
ditions, the control system and the calibration. Finally, the chapter describes the
aspects which should be considered in the development of a testing protocol.
Keywords CEN TC248
MSAJ
Biaxial
Machine
Testing
Procedure
Protocol
Architectural fabrics
Foils
4.1 Technical Requirements
This chapter is mainly focused on the mechanical behaviour of fabrics and foils for
fabrics and composites have been considered as possible
fields of interest for the
application of the testing apparatuses and procedures considered in this topic. Thus,
the technical solutions discussed here are potentially suitable for the testing of a
wide range of foils, fabrics made by high tenacity yarns of polyester, aramid,
polyamide or polypropylene, non-wovens or fabrics for furnishing or interior
design.
As highlighted in the previous chapters, the architectural solutions adopted for
membrane structures are mostly based on a form active structure, which means that
the load bearing capacity depends on the level of pre-tension introduced into the
material and the level of curvature of the surface (Bridgens et al.
2009
; Bridgens
and Birchall
2012
).
For this reason the understanding of the mechanical properties of these materials
plays a fundamental role in each phase of the realisation of these structures. The
material response is investigated under different load ratios in warp and
fill directions,
and following several loading paths according to the possible stress conditions.
