Bashar S. Mohammed

The Effects of Opening on the Structural Behavior of Masonry Wall Subjected to Compressive Loading - Strain Variation

The area around openings in the form of doors, windows and opening for mechanical and electrical services in axially loaded structural masonry panels are locations of strain concentration. In order to capture the true distribution of strains in discontinuous regions such as opening, test was made to measure the surface strain variation around the opening in masonry panels subject to compressive load using uniaxial foil strain gauges. Experimental results were compared with results of finite element analysis. Measured strains near the opening boundary showed high localized strain concentration near the opening boundary, which reduce as the distance from the opening boundary increase. Analytical results were in good agreement with the experimental results, where the lowest correlation factor is 0.715. Key Word: Masonry, Strain measurement, Strain concentration, Foil strain gauge, Finite element analysis.

Application of Response Surface Methodology in Finite Element Analysis of Deflection of Pretensioned Inverted T-Beam with Web Openings Strengthened with GFRP Laminates

A precast, prestressed concrete girder with circular web openings allows building service systems (mechanical, electrical, communications, and plumbing) to cross the girder line within the member’s depth, reducing a building’s floor -to-floor height and the overall height of the structure. These height reductions have the potential to improve the competitiveness of total precast concrete structures versus other types of building systems. The experimental program reported in this paper tested three inverted -tee girders with circular web openings strengthened with GFRP to failure to evaluate the openings’ effect on girder behavior. The test girders were designed using available recommendations in the existing literature. Using ANSYS, finite element models were developed to simulate beam deflection behavior. Accuracy of the model is assessed by applying it to prestressed beam tested in this research. Comparison of analytical results with the available experimental results for load–deflection relationships show good agreement between the finite element and experimental results. Polynomial mathematical model, generated using various combination parameters using multiple regression analysis were found to be statistically significant. Parametric study using response surface methodology through finite element analysis may form efficient approximation to immediate deflection.

Interaction diagram and response surface plot of pretensioned inverted T-beam with circular web openings

This paper presents the results of a research project aimed at providing standard circular web openings to the popular precast pretensioned inverted T-beam. Opening diameter and placement and required materials strengths were investigated. In this paper, the non-linear analysis, interaction diagram and deflection response surface plot of simply supported pretensioned inverted T-beam with circular web openings are presented. Two design parameters are varied that is: opening location and numbers of openings. The results from non-linear finite element analysis were substantiated by test results from five pretensioned inverted T-beams with web opening and one solid beam. Good agreement is shown between the theoretical and the experimental results. The effect of openings on the behaviour of such beams at different stages of loading are presented. The test results obtained from this investigation show that the performance of the specimens with web openings was almost identical to that of the specimen without web openings. An algorithm which is written to plot interaction diagram for estimating the cracking load is proposed. Deflection response surface plots using general factorial design are also presented.