Jafar’s main areas of interest and expertise lie in (i) infilled frames, (ii) masonry structures, (iii) concrete sandwich panel structures, (iv) large-scale experimental testing of structures and (v) nonlinear finite element modelling.

A few past and current research projects can be summarized as follows :

Evaluation of roof diaphragm effect on seismic behavior of masonry buildings

University of Guilan, (2008-2010)

Abstract:

Masonry buildings built with load bearing walls have been widely designed and constructed in many parts of the world mainly due to 

economical reasons. In order to simplify their analytical model, many engineers utilize rigid diaphragm assumption for modeling of roof decks. In the present study, the behavior of diaphragms under lateral loading has been investigated. A case study was conducted to evaluate the effects of roof diaphragm on the seismic behavior of unreinforced masonry buildings (URMB). Since the majority of masonry buildings have been roofed with concrete joist slabs or jack-arch flooring systems, calculations were performed by assuming both rigid and flexible behavior. Phenomena such as distribution of lateral load, and overall seismic performance of URMB with both rigid and flexible diaphragms were examined in this study.

Reconstruction of masonry buildings in the historical city of Masouleh using traditional materials

PADIR Sazeh Omran CEC, (2011-2012)

Abstract

The city of Masouleh is a historical site located in north of Iran due to preserving its originality in architectural and urban identity. In 2007, this historical city was inscribed on the UNESCO World Tentative List. In this study, besides describing the main architectural and structural features of Masouleh buildings, practical experiences in restoration of houses using ancient material and traditional construction method were investigated. In addition, the Nonlinear Static Analysis (NSA) of a building, as a case study, was carried out and the results showed that seismic resistance of masonry buildings can be acceptable for Life Safety (LS) performance level.

Research (2012-2017)2-min

Experimental and analytical investigations on the seismic response of steel frames infilled with concrete sandwich panels

University of Guilan, (2012-2017)

Abstract

The aim of this research was to study the nonlinear-seismic behaviour of Concrete Sandwich Panel-Infilled Steel Frames (CSP-ISF). It was planned to identify the most important parameters affecting the lateral load-bearing capacity of this structural system. To this end, the research project was conducted in three main phases:

The first phase focused on experimental investigation of the seismic behaviour of CSP-ISFs subjected to in-plane lateral loads. Five large-scale, single-story and single-bay steel frame specimens including four infilled frames along with one bare frame, were constructed and tested under in-plane cyclic lateral loading. Two main factors, i.e. aspect ratio and frame-to-panel interface condition, were considered in this phase. It was found that addition of sandwich panels leads to a considerable increase in the lateral

stiffness and strength, energy dissipation capacity as well as equivalent viscous damping ratio of the steel frames. Moreover, when the infill panel was separated from the bounding frame, the results showed that the infilled frame with full connection between the infill and frame behaved quite differently to that of specimen with a discrete interface connection.

The nonlinear analysis of CSP-ISFs subjected to lateral loads was studied in the second phase through developing a 2D finite element (FE) micro-model using DIANA software. After validation of the numerical model by experimental results, the influence of parameters such as compressive strength and thickness of infill, bounding frame stiffness, vertical load, steel wire mesh in infill, number of spans and presence of central opening on the in-plane behaviour of CSP-ISFs were investigated.

In the third phase, a simplified analytical method was presented to predict the lateral stiffness and maximum strength of CSP-ISF. Based on the present experiments, structural performance levels required for Performance-based Analysis were also proposed for concrete sandwich panel used as infill walls. Furthermore, the fundamental period of vibration was calculated for CSP-ISF specimens.

Out-of-Plane behavior of masonry infilled RC frames

Tabriz Islamic Art University, (2018)

Abstract

Masonry Infills are assumed as non-structural elements and are not considered in the design process of the infilled frames while their presence can affect the local or global behavior of infilled frames. In this project, the out-of-plane behavior of masonry infilled frames were studied numerically in the finite element (FE) software of DIANA. To have an accurate FE model, the numerical model was validated based on the experimental results. The influence of different parameters such as presence of central opening and Infill’s mechanical and geometrical properties were thoroughly investigated.

Current Research Projects

Experimental and numerical modal analyses of a traditional windcatcher in Yazd, Iran
               ——————————–

Seismic analysis and strengthening of chimneys of Khosravi Leather Factory, Tabriz, Iran
               ———————————

Seismic vulnerability assessment and rehabilitation of historic Church of Sohrol, Shabestar, Iran
            ———————————

sjhashemi

ابتدا باید وارد حساب کاربری خود شوید