Abstract:  Steel structures are widely used for buildings due to the advantages of high strength, good ductility and fast fabrication and erection. However, unprotected steel structures suffer serious damage or even collapse in a fire disaster due to the progressive deterioration in both strength and stiffness of structural steel with increasing of temperature. To protect life and reduce fire damage to property and financial loss, a steel structure must be designed to have the ability to sustain the applied design loads without the occurrence of excessive deflection or even failure in structural members for a specified period of time in the case of a fire. In this paper, the Improved Applied Element Method (IAEM), which was originally developed as an effective analysis technique of large-scale structures up to complete failure under different hazard loads, has been progressively developed to carry out modeling the behavior of plane frame steel structures in fire. The paper presents the methodology of a new approach for thermal analysis of the large deflection behavior of steel structures at elevated temperatures. IAEM has been developed to cover both geometric and material nonlinearities, including the changes to material properties as temperatures increase. Rigorous treatments of thermal analysis in plane frame steel structures are illustrated. The effectiveness and validation of the proposed approach are demonstrated by comparison its results with those previously obtained by benchmark experiments or by other independent computer software. The IAEM is a useful tool to perform intensive parametric studies aimed at a deeper understanding of the behavior of steel structures under elevated temperatures. Moreover, it is considered the first implementation of the thermal analysis in the filed of Discreet Element based approaches (276).

 Said Elkholy and Kimiro Meguro, Numerical Modeling Of Steel Structures In Fire Conditions Using Improved Applied Element Method, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan. Paper in progress.

Abstract: As an approach to the problem of seismic vulnerability evaluation of existing buildings using the predicted vulnerability method, analytical procedures can be applied to produce vulnerability curves for different building classes. For some building types, mainly masonry structures, the development of those curves will be complicated and time consuming if a Finite Element-based method is used. This is because the model has to represent the structural geometry and relationships between different structural elements through the element connectivity. Moreover, the FEM may not be able to represent the large displacements and separations in progressive collapse simulations, properly. Therefore, the Applied Element Method that combines the advantages of FEM with that of the Discrete Element Method in terms of accurately modeling a deformable continuum of discrete materials is used here to develop vulnerability curves for those challenging building classes. The incremental dynamic analysis of a 6-storey industrial masonry building built in 1906 in Montreal, Canada has been carried out using 14 sets of synthetic and real ground motions representing three M, R categories. The application of the incremental dynamic analysis method makes it possible to thoroughly calculate displacements and observe collapse progress under seismic loads. first-mode-dominated masonry building, period and inter-storey drifts are chosen as intensity (IM) and damage measures (DM), respectively. Intensity and damage measures are pointed on the IDA curves at the three structural performance levels, immediate occupancy, life safety, and collapse prevention, for each ground motion. The statistical analysis of those points is then carried out to determine means and standard deviations of the building’s vulnerability curve for each structural performance level. Those vulnerability curves are compared with the vulnerability curve data for masonry buildings provided by NIBS in MR1 Technical and User's Manual Those scores actually correlate potential structural deficiencies with structural characteristics for the studied building. In a larger scale, those vulnerability scores are used in the probabilistic seismic vulnerability evaluation of the building under study by comparing its seismic response with different seismic demands.

 A. Karbassi, M.-J. Nollet:  Development of Seismic Vulnerability Scores for Masonry Buildings Using the Applied Element Method. Paper in progress.

Abstract: Bridges are critical to the transportation system expecially at the time of crisis.  They are essential for rescue missions, evacuations, and rapid distribution of aid and medical supplies. Bridges are highly visible and accessible structures which make them valued potential targets for terrorist attacks as thier destruction could have significant impact on the nation.  An efficient security system can minimize the potential of terrorism, yet it will not completely eliminate the threat.  Consequently, critical bridges should be protected and designed to mitigate probable blast hazards.

The primary objective of this investigation is to analyze the effect of blast loads on critical bridge components and bridge global response, and propose protection measures for mitigating blast hazards. This investigation presents an overview of the characteristics of blast loads, pressure distributions, wave propagation and reflection, energy dissipation, and the factors affecting the behavior of structural elements subjected to blast loading.

Key Words: Response, structures, subjected, protection, techniques, mitigate, hazards, bridges. 

Yahia M. Tokal-Ahmed: Response of Bridge Structures Subjected to Blast Loads and Protection Techniques to Mitigate the Effect of Blast Hazzards on Bridges, Ph.D Thesis, Rutgers University, 2009.

Abstract: Progressive collapse is a failure mode of great concern for tall buildings, and is also typical for building demolition. Engineers are nowadays more and more interested in structures integrity estimation and collapse theory finding, in order to develop strategies for increasing or decreasing the progressive failure. A new method has been developed, for the last years, called Applied Element Method, which has a large practicability for failure modelling. This paper has two main goals: (i) a short presentation of the Applied Element Method and (ii) the presentation of a case study both as mathematical modelling and as demolition of structure.

Keywords: Progressive Collapse, Demolition, Explosion, Modelling, Simulation, Applied Element Method.

Lupoae, Bucur: Building Demolition - Positive Aspect of Progressive Collapse, MTA Review, Vol XIX, No. 4, December 2009.

Abstract: The collapse of non-engineered masonry is one of the greatest causes of death in major earthquake events around the world, yet by definition non-engineered structures remain largely outside of the scope of modern engineering research. For this reason, the majority of those at risk remain so, despite the many recent advances in earthquake engineering. This project therefore aims to:
• Test a recently developed retrofitting technology (polypropylene meshing), specifically aimed at preventing the collapse of adobe (mud brick) buildings under strong earthquakes.
• Demonstrate the application of a recently developed numerical tool, the Applied Element Method, in dynamic modelling of blocky masonry into the collapse stage.
• Implement the proposed retrofitting technique in a seismically active region of the Kathmandu Valley, Nepal.

Joshua Macabuag: Extending the Collapse Time of Non-Engineered Masonry Buildings Under Seismic Loading, The Structural Engineer 1 April 2008.

Abstract: Within the past 40 years, abnormal loadings resulting from natural hazards, design flaws, construction errors, and man-made threats have induced progressive collapse in structures all over the world. As progressive collapse behavior has become more prominent, it has made the necessity for design and analysis tools evident. In effort to provide one of these tools, Applied Science International, Inc. introduced its Extreme Loading® for Structures (ELS®) software, capable of progressive collapse simulation.

This research evaluates the effectiveness of Extreme Loading® for Structures as an emerging, nonlinear dynamic analysis software package in modeling progressive collapse scenarios. The ELS® software utilizes the Applied Element Method (AEM) of numerical analysis, separating it from other available software packages. The software and analysis methodology’s accuracy are investigated through simulation of two structural implosions. Comparing the predicted response to the documented response, each scenario is evaluated by analyzing the material models, failure criteria, local structural behavior, and global collapse behavior.

Griffin, Joshua Wayne: Masters Thesis - Experimental and Analytical Investigation of Progressive Collapse through Demolition Scenarios and Computer Modeling, March 2008.

Hoon Park, Chul-Gi Suk, Seung-Kon Kim: A Study on Explosive Demolition of a Cylindrical Silo Structure, Korea Kacoh 2008.

Hyung-Dong Min,Jong-Ho Park. Young-Suk Song, Hoon Park: The Case Study of Explosives Demolition at Chung-Ang Department, Korea Kacoh 2008.

Abstract: Progressive collapse simulation is the latest challenge facing today’s engineers wishing to assess the integrity of structures and to develop any necessary progressive collapse mitigation strategies. To this end, an ideal progressive collapse numerical simulation should include the involvement and integration of the following elements: a modeling of the structural, non-structural components, and the load threat, the separation of parts, as well as the possible collision resulting from falling debris.

A. F. Elragi, N. M. Abdel-Rahman and Hatem Tagel-Din: Numerical Models for Upgrade of Reinforced Concrete Beams with Bonded Composite Laminates, 4^th International Conference on Civil and Architecture Engineering, Cairo, Egypt, Volume 1, May 2002.