http://hdl.handle.net/123456789/172 Wed, 06 May 2026 21:29:28 GMT 2026-05-06T21:29:28Z http://hdl.handle.net/123456789/221683 Title: Experimentally investigating the structural capacity of slender web tapered built up plate girder with web opening Authors: Ebid, Ahmed M; Ibrahim, Sherif M.; El-Aghoury, Mohamed A; Taher, Mohamed Abstract: Built-up plate girders are widely used in structural applications where hot-rolled beams may not provide sufficient strength or stiffness. To achieve a cost-effective design, tapered plate girders are often employed, allowing for an optimized distribution of material by gradually varying the web depth along the span. In many practical applications, web openings are introduced to accommodate service ducts, utilities, and weight reduction, making them an essential feature in modern steel structures. However, while design codes provide well-established methods for prismatic girders, the web behavior of tapered girders with web openings remains insufficiently investigated, leading to gaps in existing predictive models. This research presents a novel equation to estimate the web capacity of tapered plate girders with web opening, considering parameters such as the panel aspect ratio, web opening size to panel average height ratio and tapering ratio. The equation was validated with the experimental results giving a maximum error of 8%. A comparative study was conducted using different methodologies of steel design standards and previous researches to evaluate their results with the experiments. The results of these methodologies demonstrated significant contradictions. Where some standards underestimated the web capacity by up to 58% while some others overestimated it by up to 45%. The presented formula gives significant improvement in designing the steel plate girders with web opening, hence in structural design. Future research may consider enhancing the equation taking into consideration widening the range of values for taken parameters or by considering more parameters regarding the girders' geometry, loading and boundary conditions. Thu, 31 Jul 2025 00:00:00 GMT http://hdl.handle.net/123456789/221683 2025-07-31T00:00:00Z http://hdl.handle.net/123456789/221682 Title: Experimental and numerical investigation of cold-formed sigma sections subjected to bending and torsion moments Authors: Ismail, Mohamed; Hammad, Ali; Ibrahim, Sherif M. Abstract: Cold-Formed Steel (CFS) has gained prominence in the construction industry due to its sustainability and cost-effectiveness. This paper explores the behavior of CFS sigma beams, a monosymmetric profile that deviates from lipped C-sections by incorporating web stiffening to enhance structural efficiency in their applications as flexural members. The beams' behavior is experimentally investigated under eccentric loading, caused by load application offset from the cross-section shear center, combining bending and torsional moments. A total of 24 experimental tests were conducted on simply supported sigma beams with various profiles subjected to eccentric load at mid-span, varying both the thickness and the loading eccentricity. The test setup was designed to induce the required loading and end conditions. These tests were then utilized in the construction of numerical models using Abaqus non-linear finite element analysis (FEA). The numerical models were validated against the experimental test results, showing good agreement in terms of ultimate strength, lateral deformations, and failure modes. Finally, a comparative analysis was conducted comparing the experimental outcomes and the GB 50018-2002 for bending and torsion. The comparison showed that the current code underestimates the sectional capacity by 67 % on average. A modified design equation is proposed to predict the sigma sections subjected to both bending moment and torsion. The proposed equation improved the accuracy significantly, with only 13 % lower estimation on average. Mon, 01 Sep 2025 00:00:00 GMT http://hdl.handle.net/123456789/221682 2025-09-01T00:00:00Z http://hdl.handle.net/123456789/221681 Title: Shear capacity of corrugated web steel beams strengthened with CFRP strips Authors: El Aghoury, Mohamed A; Dyab, Alshaymaa K; Ibrahim, Sherif M.; Saddek, Amr B Abstract: In recent years, there has been significant advancement in strengthening techniques for steel structures using carbon-fiber reinforced polymer (CFRP). While numerous studies have focused on CFRP strengthening of steel beams with flat webs, similar investigations on corrugated web steel beams (CWSBs) remain limited despite their increasing application in various steel structures. This study presents numerical and analytical investigations aimed at evaluating the effectiveness of CFRP strengthening for CWSBs and developing a design procedure to predict the shear buckling capacity of strengthened CWSBs. The research employs a finite element (FE) model developed using ANSYS software, validated against previous experimental work by the same authors, which accurately reflects the overall behavior of CWSBs. A parametric study is conducted on 105 CWSBs using the validated FE model to assess the impact of various geometrical parameters, including beam web slenderness ratio, length and thickness of CFRP strips, and different CFRP strip schemes. Results demonstrate that CFRP strengthening can enhance the shear capacity of CWSBs by up to 74.50%. The study identifies the arrangement of CFRP strips on both sides of the web as the most effective parameter for controlling the efficiency of the CFRP strengthening technique. Conversely, changes in CFRP strips up to 70% of web height have minimal effect. A proposed design procedure for predicting the design shear buckling strength of CFRP-strengthened CWSBs shows good consistency with FE model results. Mon, 16 Dec 2024 00:00:00 GMT http://hdl.handle.net/123456789/221681 2024-12-16T00:00:00Z http://hdl.handle.net/123456789/221475 Title: Dynamic Modeling for Analyzing Cost Overrun Risks in Residential Projects Authors: Taha, Ghada; Sherif, Ali; Badawy, Mohamed Abstract: The primary concern in the residential projects industry is to implement a project with the optimal quality within the planned schedule and planned budget. Simulation is considered an effective tool for analyzing the construction process in residential projects because it considers behavior of feedback as well as the frequent changes with time. This study aimed to develop a system dynamics (SD) model to estimate the overall cost overrun risks in addition to allowing decision makers to anticipate the feedback of indefinite numbers of what-if questions considering highly dynamic uncertainty and dynamic risk interactions influencing residential project performance that traditional methods may miss. Major risks that can cause cost overruns in residential projects were initially identified through a review of related literature, a questionnaire survey, and several workshop rounds. Then, the model boundaries' variables were identified, and a qualitative model was created through a causal loop diagram (CLD). Afterward, mathematical equations and relationships between variables were established in a stock-flow diagram. The proposed model consists of five subsystems to simulate how changes in dynamics of inspecting the completed works from the contractor's and the consultant's points of view; the probability of scope change; the material resources management process; the workforce hire-quit cycle; and the work-rework cycle can influence the cost performance of a residential project. The model was tested and validated using data derived from a residential project located in Egypt, and testing results showed that the simulated behavior of the model is the same as the actual behavior of the project. The sensitivity analysis results showed that increasing workforce more than the desired, scope changes, and rework rate are the parameters that cause the largest cost performance regression in residential projects. Thu, 01 Sep 2022 00:00:00 GMT http://hdl.handle.net/123456789/221475 2022-09-01T00:00:00Z