English version: MaNACoH was written by Mathias Fantin for the second French conference on history construction that took place in Lyon in January 2014, with the help of Thierry Ciblac, teacher-researcher at MAP-Maacc Laboratory in Paris (CNRS-MCC UMR 3495). Manacoh is an open-source software addressed primarily to scholars and students who study ancient methods for assessing the stability of masonry vaults, in the field of construction history. It is well suited to study structures that have a strong 3D geometry (for example ellipsoid vaults, as opposed to simple arches that can be studied easily in 2D). Classical 2D geometries can be studied as well. It uses the thrust network analysis. This method replaces the well-known inverted catenary by an inverted net, called thrust network. Passing from 2D to 3D widens the possible equilibrium solutions that can be searched. The drawback is the increased difficulty to solve the equilibrium equations in three dimensions. Manacoh is an all-in-one tool to study 3D structures: it builds the geometry for parametric pre-set examples, solves the equilibrium equations, and offers the possibility to explore various equilibrium solutions, through optimization strategies. 9], and then extended by Block in 2009  under the name of thrust network analysis1. Tools using thrust network analysis exist (Van Swinderen et Coenders 2009 , Rippmann et al. 2012 ), and several advances and extensions have already been proposed in recent years, concerning the optimization procedures (Vouga et al 2012 , Block et Lachauer 2014 ), and/or the related variational formulations (Fraternali 2010 , De Goes et al. 2013 ). Our implementation of the technique focus on the field of construction history. It aims at providing a tool capable of reproducing various equilibrium solutions of published studies of historic interest, using for each of them their own stability criterion. Also, the study of more complex 3D geometries using these historic criteria is possible. The signification of the thrust network was re-evaluated with respect to the line of thrust and the line of pressure. To do so the geometric characteristics of the joints were taken into account, whereas previous studies usually disregard this aspect of the modelisation and consider only vertical joints. Thus Manacoh is designed primarily to study existing structures, the drawback being that it offers only restricted possibilities for form finding of innovative 3D forms. The main application of Manacoh so far has been to investigate existing studies of various authors: Bossut 1776 , Rankine 1858 , Eddy 1877 , Durand-Claye 1880 , Wolfe 1921 , Heyman 1967  etc. Equivalent formulations in term of optimization under constraints have been formulated, and checked against results published in scientific literature. Although there is an obvious risk of anachronism by studying all these authors with a numeric tool, this technique proved fast and effective to compute results that help understand and compare these historic methods. It allows also to rediscover forgotten techniques that would be very difficult to apprehend without a numerical tool (Durand-Claye is a good example in that respect). This manual has been divided in four chapters. The first chapter provide the context of this work, the installation procedure of the program, and a quick overview of the program with a basic example. The second chapter describes the program use, its functions, options, and results. The third chapter addresses the theory of the thrust network analysis, its signification with respect to the line of thrust and line of pressure, and the definition of coefficients of safety. The fourth chapter examines various examples from construction history, in order to demonstrate the possibilities of the program. These examples were studied as a preparation for an oral communication by Mathias Fantin and Thierry Ciblac at the second French conference on history construction that took place in Lyon in January 2014.
Download Manacoh and its user manualThe program and its user manual are available for download:
Versions historyv1.0.1 (10/02/2014) macros "Compute typology" and "Compute equilibrium" are not executed automatically after macro "Create Geometry" anymore. No change to the user manual v1.0.0 (30/01/2014) first release
Article mis en ligne le : 12/01/2014.
Révisé le : 10/02/2014.
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