The paper presents new studies on numerical modeling (FEM) for beam-to-column behavior under sagging and hogging bending moment when the framework is exposed to service and unexpected loads that may cause a column loss scenario. This investigation is focused on four bolts end-plate joints with 10 mm thickness which are proven experimentally to have more ductile behavior than other end-plates joints (6, 8 bolts), spite of their weakness to transfer the unexpected loads from the initial state to a residual state of the stable equilibrium, that leads to a failure of limited floor area to adjacent joints when tested experimentally (Saleh, 2014). FEM technique used in this research is an extension of the previous technique and is characterized by the use of a more sophisticated technique than the previous, discovered from the result of continuous research and the use of all the options available in the new version of commercial ABAQUS/CAD software. The elements are designed using multiple layers of specific elements of a brick arranged in such a way that the mesh nodes of the tiles should coincide with certain layers with the top of the shear inlay and in line with reinforcement, not as the former study that used thick shell elements to model the reinforced concrete slab with total negligence of reinforcing steel and bolts between the slap and the beam. This investigation is very complex because of highly nonlinear effects associated with the prediction of joint performance, such as structural imperfections, huge displacements and large rotations, inelastic properties of steel and concrete, bonding effects between steel and concrete, friction between …

The paper presents studies on experimental investigation of beam-to-column joint behavior in standard and exceptional events situations. This assessment is done to form a picture of the general the behavior of full scale frameworks at both the level of the global behavior of the framework, in terms of its load-displacement characteristic, and of the local behavior of joints in terms of their moment-rotation characteristics, and evaluates details about the interaction of the joint elements and how they work together in a balanced manner, during exceptional events, this study concerns the joints which are subject to the collapse and also includes the behavior of joints in the neighborhood of the collapse. The intricacy of such investigations appear from nonlinear effects associated with the outlook of joint behavior or functioning, such as structural shortcomings, large displacements and rotations, inelastic properties of steel and concrete materials, the effects between steel and concrete, and slip between concrete and structural steel, through others. The paper addresses these problems using two types of joints flush and extended end-plate with four and eight bolts and provides recommendations and reasoning for the behavioral techniques for the evaluation of joint moment-rotation response when exposed to negative and positive moments together.

The construction industry has become more complex due to changes in technology and the greater emphasis placed on satisfying green requirements. The design phase is the most important phase in determining the green performance of building projects. The performance of the design team is crucial. The selection of a design team should be based on a set of criteria. Therefore, a competent design teams is required to have a good understanding of environmental issues. Design teams require a range of competences such as skills of environmental assessments, initiatives and environmental background as the basis for design decisions. In addition, success of building projects greatly depends on the client’s performance. The performance of clients is crucial since decisions made will influence the overall project performance. The quality of clients’ representatives has potential influence on design team performance. In designing green buildings client’s attributes are critical factors to high performance of building projects. The propose of this study to identify the significant associations between variables of design team attributes and client qualities. To achieve mentioned aim a questionnaire survey was conducted to collect data required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used for Rasch modeling to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. The results indicate that the influence of Clients’ Qualities on Design Team 

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Aspects related to robustness of steel frameworks with semi-rigid steel and steel-concrete composite joints are dealt with. Experimental investigations were carried out for sub-frames fabricated in technical scale. Pushdown tests for steel subframes simulated the joint ability to transfer the bending moment and axial force under a column loss scenario. Tests on composite sub-frames were arranged in two stages. The first one was related to a service stage when the slab was under a gravity load and the column to be removed supported. The gravity load was sustained in the second stage when a column loss scenario was simulated. Experiments have shown that composite flush end-plate joints may not be robust enough since their low strength under sagging bending, despite of good ductility, does not allow for the redistribution of internal forces in order to achieve the equilibrium in the residual state after static column removal. Contrary, symmetrical steel and composite joints with extended end-plates on both sides of beam flanges seem to be more robust, despite of their lesser ductility. Robust bending behaviour is possible because extended end-plate joints exhibit a better balance between the strength and rotation capacity that allows to achieve the equilibrium state in case of a static column loss event.

Progressive building collapse occurs when failure of a structural component leads to the failure and collapse of surrounding members, possibly promoting additional collapse. Global system collapse will occur if the damaged system is unable to reach a new static equilibrium configuration. The objective of this research is to identify and investigate the importance of issues related to the unexpected collapse resulting from the loss of key elements of the structure (a column or columns, for example). In this research study there are examined on the entire frame including details of the column loss scenario and also the influence of the ductility and strength of beam-to-column joints adjacent to the location of such as incident. The study also includes catenary action in beams resulting from collapse and its impact on the adjacent joints and reports on the comparison of negative and positive moments in joints. In addition, it records the important notes associated with the state of collapse and parts of this research include the conformity of numerical and analytical results, the ratio of credibility and conformity of results and the test. This thesis reports in detail on the experimental and numerical investigations of the behaviour of steel and composite joints, which aim to develop common solutions with regard to the joint semi-rigid and partial strength properties that might allow for significant rotations and the redistribution of internal forces in structural system when there was a damage to its key element such as a column. Investigations of steel and composite joints with regard to their ductile behaviour are presented. Thereby special attention is paid to shaping of …

ABSTRACT

In order to capture the effect of joint progressive stiffness degradation with the hardening effect taken into account, the three parametric continuous model is adopted hereafter for the analytical formulation. The current paper is an extension of the previous work (Gizejowski et al. 2012) giving all the details of the developed model together with a calibration procedure for basic model parameters. Experimental data used was obtained from laboratory tests carried out at the Warsaw University of Technology for beam-to-column joints of different reinforcement ratio. The results of calibration exercise as well as the values of calibrated model parameters are given for practical application.

Problem statement: In the construction industry, success of building projects greatly depends on the client’s performance. The performance of clients is crucial since decisions made will influence the overall project performance. Typically, clients are represented by managerial and technical representatives during the design process. They play major roles in conveying required information to the design team regarding their future project. The quality of clients’ representatives has potential influence on design team performance. In designing green buildings client’s attributes are critical factors to high performance of building projects. Attributes such as knowledge and experience on green buildings, commitment level to green and clients’ ability to participate and manage design process are the key factors to produce green design. The propose of this study to identify current performance level of clients of building projects and establish key clients’ attributes influencing green design performance. Approach: To achieve mentioned aim a questionnaire survey was conducted to collect dada required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used for Rasch modeling to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. Results and Conclusion: Client qualities in general were low, client communication with design team; client involvement and ability to coordinate design process were moderate. However, Knowledge and experience on green …

The design phase is the most important phase in determining the green performance of building projects. The performance of the design team is crucial. The growing importance of sustainability globally necessitates the inclusion of green criteria in the design team selection process. Therefore, a competent design teams is required to have a range of attributes as the basis for design decisions. The propose of this study to identify current green design performance level of design teams of building projects and establish key design attributes influencing green design performance. To achieve mentioned aim a questionnaire survey was conducted to collect dada required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. In general, design team attributes were moderate (3.32). The general design team attributes were high such experience (3.81), communication (3.43) and leadership effectiveness (3.48). However, green attributes of design team were moderate such as green knowledge (2.98), green skills (3.13) and green initiatives (2.84). The result indicates that most design teams have inadequate knowledge and skills to produce high green design performance of building projects. Therefore, to overcome green design complexity, careful selecting design team members and more education and training courses on green building are required to deal with green design requirements.

The aim of this work was to investigate whether the Malaysian current building projects are considered as “Green Designs”. To achieve this aim a questionnaire survey was conducted. A sample of 274 respondents is covered, which included architects and engineers in the building design and consultancy sectors. WINSTEPS software is used in Rasch modeling to determine the validity and reliability of the data. Descriptive data analysis (quantitative and qualitative) is done. The results reveal that design green building performance, in general, energy efficiency, and indoor air quality requirements are considered moderate. The majority of the designed buildings are with low utilization of recycled and reused materials. Moreover, high utilization of regional materials, low consideration to water efficiency requirements and environmental innovations are also moderate. Design team attributes are the key factors to improve green design performance. Client quality play major role to enhance design team attributes. Therefore, effective Design team attributes and client’s qualities may increase performance of the design green building performance in order to enhance building performance and reduce building impact on environment.

Eurocodes [1], [2] cover presently only the so-called basic design situations where the beam-to-column joints are subjected to hogging bending with a negligible influence of the axial force. Design requirements for structural robustness in case of exceptional or extreme actions are being developed in which the joint ductility demand is one of the primary requirement [3][6]. Localized structural damage due to these actions may propagate through a large portion of a structural system causing its entire collapse or the progressive collapse process may be restricted to the relatively small region that is in proportion to the load effects caused. The latter might be provided by design ensuring the ability of transfer the so-called tying forces. Eurocodes do not give any guidelines on how to calculate the tying resistance of joints, mainly because of lack of experimental evidence on the joint ductility under extreme actions. For robust design, joints need to pose the rotation capacity required for inelastic redistribution process to take place on the so-called alternative equilibrium path. The capability of a structure to sustain local damage is evaluated by a notionally conducted removal of its column(s) and checking whether the local damage may be absorbed by the deteriorated structural system. This requires investigations conducted into the behaviour of joint responses to sagging bending accompanied by an axial tying. This paper is concerned with experimental tests of steel and steel-concrete composite sub-frames through which the beam-to-column joint behaviour in typical standard and exceptional design situations is possible to be evaluated. Problems related to the joint strength, stiffness and rotation capacity response under sagging moment in case of the column removal that simulates the frame system behaviour in an exceptional situation are addressed and conclusions drawn.