CONTRIBUTION OF A FORM-FIND SHAPE OF PIN-ENDED ARCH

Asal Pournaghshband

doi:10.5937/jaes15-13243

Asal Pournaghshband Asal Pournaghshband PhD graduate, University of Warwick School of Engineering, University of Warwick, Coventry CV4 7AL, UK E-mail address: apournaghshband@gmail.com Tel: +44 (0)7899 838583

DOI: https://doi.org/10.5937/jaes15-13243

Keywords: shaping, loads, displacement, optimal shape, Moments,

Abstract

This paper presents the numerical application of a form-find two-pin arch shape with constant cross-section made of concrete. This investigation is carried out for arches with any span to height (L:h) ratio and any ratio of uniformly distributed load (UDL) to self-weight (SW) in which the geometry is a function of loading. The form-find arch shape is the one comprising only axial forces named momentless arch in this paper. The contribution of such a form-find arch is shown in a case study firstly through comparing its deflection with the most favourable arch shape under UDL:SW > 1which known as parabolic form. Secondly, the first failure of arch cross-section for form-find arch is evaluated against parabolic one subjected to the same permanent load. Results show the maximum vertical displacement of the form-find arch to be almost half of the maximum vertical displacement of its parabolic equal. To have the same maximum displacement, the thickness of the form-find arch could be reduced to half of its initial value leading to mass reduction. Furthermore, the former arch shows the first cross-sectional failure for 24% higher vertical displacement at the arch crown compared to parabolic arch.