A Fully Graphical Approach for Limit State Analysis of Existing Structures: Application to Plane Elastic-Plastic Bended Structures and to Plane Masonry Arches

ABSTRACT

When classical elastic analysis fails to model correctly the structural behavior of historical masonry structures because of the brittle, rigid, anisotropic, and inhomogeneous characteristics of their building material, equilibrium-based limit state analysis constitutes an efficient alternative for their structural assessment. The lack of knowledge about the history of loading makes the actual state of stresses impossible to determine for these statically indeterminate structures. However, Plastic Theory provides a powerful theoretical framework that defines in a rather simple way the structural safety level. The lower-bound theorem of plasticity can be applied using graphic statics because it ensures that equilibrium and yield conditions are respected when applying specific constraints to the nodes of the reciprocal diagrams.

This article focuses on limit stat analysis of statically indeterminate structures by means of geometrical considerations using graphic statics reciprocal diagrams. For linear-bended structures, we show that: (1) the conditions of stability can be defined graphically by constructing safety domains; (2) collapse modes can be identified and related to specific reciprocal polygons; and (3) the exact value of the collapse load factor can be deduced graphically from the diagrams. Finally, we extend these results to plane masonry arches in relation with the classical thrust line approach.     

Between clinical medicine and the laboratory: medical research funding in France from 1945 to the present

By focusing on funding methods, this paper considers the way in which medical research eventually led to the science-based medicine that is prevalent in France today. This process seems to have taken place in three stages during the second half of the twentieth century. In the 1940s and 1950s, two major events occurred. The first was the creation of a national health insurance fund in France, which opened up new reasons for, and ways of, funding medical research. The second was the development of antibiotics, which triggered a revival of clinical medicine. In the 1960s and 1970s, a proactive government science policy allowed the life sciences and medical research to come together in the wake of a burgeoning new science: molecular biology. Thus, in 1964, the creation of the National Health and Medical Research Institute (Institut national de la santé et de la recherche médicale or INSERM), destined to "molecularize" medical research, was seen as the fulfillment of the government's ambitious research policy. Today, with medicine irreversibly embedded in scientific and technical rationality, health has become a major issue in modern societies. This paper therefore touches on some of the key features of biomedical research, including the revival of funding systems for clinical research and the development of a system of research grants that was made possible by patient organizations and the creation of new funding agencies.     

Performing race and gender: the exoticization of Josephine Baker and Anna May Wong

Josephine Baker and Anna May Wong are two exceptions to white hegemony in early show business. They became the first Afro-American and Chinese-American stars in the 1920s and reached international stardom in spite of their ethnicity but also because of it. Their careers and success were based on their exoticization. Baker and Wong's exoticism has much to do with ethnicity, but also with sex and gender. Their exotic dances on stage or on screen can be considered to be forms of erotic shows. This article shows how sex, gender, and race are entangled in their movies and burlesque shows. It also discusses the ways in which the agency and the audience of the performer should be taken into account, and analyzes how these performances were both rooted in Western imaginative geographies and connected to symbolic and material spaces.