Cet article rapporte les resultats de l'application de la technique de mesure de contraintes ... more Cet article rapporte les resultats de l'application de la technique de mesure de contraintes in situ par liberation partielle a un grand pont en maconnerie de pierre, le pont Adolphe a Luxembourg du a P. Sejourne. Pour disposer les verins plats, on pratiqua douze entailles de 60 cm de large dans des sections situees pres des naissances de l'arc. La methode de mesure de contrainte par liberation partielle et restauration au moyen de verins plats s'est averee utilisable. Elle a fourni dans la maconnerie des valeurs de contraintes coherentes et realistes, bien inferieures a la resistance intrinseque. (A) (Titres en anglais, en allemand et en espagnol : Stress measurements by release of tension in the Adolphe bridge, a large arch designed by P. Sejourne - Messung der Belastung mit flachen Druckmessdosen an der von P. Sejourne entworfenen Adolphe-Bruecke in Luxemburg - Mediciones de tensiones por liberacion en el puente Adolphe de Luxemburgo, gran boveda de P. Sejourne).
As testimony of the engineering development during the industrial revolution, old riveted bridges... more As testimony of the engineering development during the industrial revolution, old riveted bridges are maintained by several policies worldwide and in some cases because of their historical importance protected. A main concern of these policies is preserving their structural integrity, which depends on a fatigue assessment of their components and assemblies. In these structures, the stress ratio considerably affects the fatigue strength, but the actual standards do not consider this fact. Some deterministic models have been proposed in order to overcome this issue. However, they are based on restrictive and empirical assumptions. Moreover, no statistical considerations are made, although fatigue strength is a random variable. In this paper, the suggested models are studied and then enhanced by statistical considerations. Finally, a statistical fatigue strength model as function of the stress ratio is proposed and applied on riveted specimens from old German Bridges and newly manufact...
Fatigue & Fracture of Engineering Materials & Structures, 2020
Old riveted railway bridges are part of the cultural and technological heritage in many countries... more Old riveted railway bridges are part of the cultural and technological heritage in many countries. The assessment of the actual behaviour and the remaining life of these structures is a key economical factor in the management of these bridges. This evaluation should take into account the evolution of the traffic loads, which have constantly increased since their construction, and a realistic estimation of the fatigue life derived from representative experimental tests.This study deals with the fatigue behaviour of riveted assemblies with specimens prepared from materials sampled in two old bridges: a railway bridge over the Adour river (France) built in 1862–1864 and the Stahringer bridge (Germany), constructed in 1895. Because all assemblies are not subjected to the same loads, this research concentrates on the influence of the stress ratio R on the fatigue behaviour. In order to quantify this influence, a comparison between the Basquin linear model and the Weibull model is perform...
Cet article rapporte les resultats de l'application de la technique de mesure de contraintes ... more Cet article rapporte les resultats de l'application de la technique de mesure de contraintes in situ par liberation partielle a un grand pont en maconnerie de pierre, le pont Adolphe a Luxembourg du a P. Sejourne. Pour disposer les verins plats, on pratiqua douze entailles de 60 cm de large dans des sections situees pres des naissances de l'arc. La methode de mesure de contrainte par liberation partielle et restauration au moyen de verins plats s'est averee utilisable. Elle a fourni dans la maconnerie des valeurs de contraintes coherentes et realistes, bien inferieures a la resistance intrinseque. (A) (Titres en anglais, en allemand et en espagnol : Stress measurements by release of tension in the Adolphe bridge, a large arch designed by P. Sejourne - Messung der Belastung mit flachen Druckmessdosen an der von P. Sejourne entworfenen Adolphe-Bruecke in Luxemburg - Mediciones de tensiones por liberacion en el puente Adolphe de Luxemburgo, gran boveda de P. Sejourne).
As testimony of the engineering development during the industrial revolution, old riveted bridges... more As testimony of the engineering development during the industrial revolution, old riveted bridges are maintained by several policies worldwide and in some cases because of their historical importance protected. A main concern of these policies is preserving their structural integrity, which depends on a fatigue assessment of their components and assemblies. In these structures, the stress ratio considerably affects the fatigue strength, but the actual standards do not consider this fact. Some deterministic models have been proposed in order to overcome this issue. However, they are based on restrictive and empirical assumptions. Moreover, no statistical considerations are made, although fatigue strength is a random variable. In this paper, the suggested models are studied and then enhanced by statistical considerations. Finally, a statistical fatigue strength model as function of the stress ratio is proposed and applied on riveted specimens from old German Bridges and newly manufact...
Fatigue & Fracture of Engineering Materials & Structures, 2020
Old riveted railway bridges are part of the cultural and technological heritage in many countries... more Old riveted railway bridges are part of the cultural and technological heritage in many countries. The assessment of the actual behaviour and the remaining life of these structures is a key economical factor in the management of these bridges. This evaluation should take into account the evolution of the traffic loads, which have constantly increased since their construction, and a realistic estimation of the fatigue life derived from representative experimental tests.This study deals with the fatigue behaviour of riveted assemblies with specimens prepared from materials sampled in two old bridges: a railway bridge over the Adour river (France) built in 1862–1864 and the Stahringer bridge (Germany), constructed in 1895. Because all assemblies are not subjected to the same loads, this research concentrates on the influence of the stress ratio R on the fatigue behaviour. In order to quantify this influence, a comparison between the Basquin linear model and the Weibull model is perform...
Uploads
Papers by Bernard Espion