No abstract

No abstract

Introduction: The heart is in a muscular organ in the middle mediastinum. According to our knowledge, there is no standard data about the anthropologic parameters of normal Iranian hearts. Hence, the aim of the present study was to investigate the normal heart size in Iranian cadavers. Methods: In a cross-sectional study, 550 cadavers (104 female/446 male) from June 2014 to July 2015 in the Razavi Khorasan province of Iran were included in the study. After approval of the Ethical Committee, cadavers were divided into 10 groups based on age groups. Length, width, weight, chordae tendineae, papillary muscles, and heart valves were measured using vernier caliper. Finally, data were analyzed using SPSS software. Results: The mean values of the demographic data were as follows: age= 42.12 ± 21.34 years; weight = 60.38 ± 15.32 kg; height = 158.14 ± 23.77 cm; and BMI = 24.66 ± 17.60 kg/m2. The mean values of the heart length, width, chordae tendineae, pupillary muscles, weight, and index of the heart were 11.41 ± 2.15 cm, 8.21 ± 4.38 cm, 19.41 ± 6.70, 5.74 ± 1.96, 247.78 ± 62.27 grams, and 5.74 ± 1.96, respectively. In addition, the circumference of the tricuspid valve, circumference of the mitral valves, and tricuspid and mitral areas were 8.80 ± 1.11 cm, 9.43 ± 1.44 cm, 4.11 ± 0.71 cm2, and 4.50 ± 0.90 cm2, respectively. Conclusion: Mean values of the heart’s length and width was similar to previous reports from western population. The circumference of the tricuspid valve was less than the textbook’s data, while circumference of the mitral valves was more than it. The study findings provide valuable information about standard data of the heart in the Iranian population, which is useful for surgeons as well as anthropologists. However, multi-center studies with a larger sample size are required to complete data about anatomical characteristics of normal hearts.

No abstract

No abstract

No abstract

The present paper introduces a mixed shear-flexural (VM) link element that is capable of modelling shear yielding, flexural yielding, and their interaction under monotonic and cyclic loadings. The inelastic deformations are modelled using the multisurfaces approach with dissimilar yield surfaces and a stiffness matrix with nonzero off-diagonal components in shear-flexural space. A new kinematic hardening and new non-associated flow rules are employed. A special girder, which has an open web in the middle, is introduced and modelled using the developed VM link element. It is shown that the results of analyses using the VM link element are in good agreement with those from a finite element analysis. Nonlinear dynamic analyses are performed on a benchmark ordinary moment frame (OMF) and its improved versions with special girders. The special girder moment frame (SGMF), which consists of special girders at the lower storeys and ordinary girders at the roof level, has better seismic performance.Key words: mixed shear-flexural (VM) link element, inelastic zone, shear-flexural interaction, cyclic loading, multisurface, special girder, special girder moment frame (SGMF), ordinary moment frame (OMF).Résumé : Cet article présente un élément de liaison cisaillement-flexion (« VM ») mixte, qui peut servir à modéliser la rupture en cisaillement, la rupture en flexion et leur interaction sous des charges monotones et cycliques. Les défor-mations inélastiques sont modélisées en utilisant l'approche à surfaces multiples avec des surfaces à différents points de rupture et une matrice de rigidité où les composantes non nulles ne se trouvent pas sur la diagonale dans un espace de cisaillement-flexion. Un nouveau durcissement cinématique et de nouvelles règles d'écoulement non associées sont utilisés. Une poutre spéciale ayant une âme en treillis au centre est présentée et modélisée en utilisant l'élément de liaison cisaillement-flexion développé. Il a été démontré que les résultats des analyses en utilisant l'élément de liaison cisaillementflexion et l'élément fini concordent bien les uns aux autres. Des analyses dynamiques non linéaires ont été effectuées sur une structure à moment spécial ordinaire (« OMF ») de référence et ses versions améliorées en utilisant des poutres spéciales. La structure à moment spécial munie de poutres spéciales (« SGMF »), comportant des poutres spéciales aux étages inférieurs et des poutres ordinaires au niveau du toit, présente le meilleur comportement sismique.Mots-clés : élément de liaison cisaillement-flexion, zone inélastique, interaction cisaillement-flexion, charges cycliques, surfaces multiples, poutre spéciale, structure à moment spécial munie de poutres spéciales (« SGMF »), structure à moment spécial ordinaire (« OMF »).[Traduit par la Rédaction] Kazemi and Erfani 1130

In the special zones of frame elements, which are used for seismic energy dissipation, inelastic interaction among the internal forces needs to be considered more precisely. This paper describes a special element called a VM link element for modeling the shear–flexural interaction in the inelastic zones of beam elements. The element may be used in the any inelastic location of frames subjected to the monotonic or cyclic loadings. The inelastic shear and flexural deformations are considered by using the multi‐surfaces plasticity concept with dissimilar yield surfaces. A new kinematic hardening and new non‐associated flow rules are introduced for definition of the plastic deformations and managing the yield surfaces translations, respectively. The special VM link element is examined for some shear links, and it is shown that the proposed model predictions are in good agreement with existing test results. An eccentrically braced steel frame (EBF), subjected to a strong ground motion, is modeled by using the beam and the proposed VM link elements, and shear–flexural interaction is investigated. Copyright © 2007 John Wiley & Sons, Ltd.