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AbstractThis study investigates the dynamic response of masonry bridges under blast-induced shock waves, focusing on the structural integrity and safety of these critical infrastructure components under extreme conditions. The research employs theoretical approaches to analyze the effects of blast-induced shock waves on masonry bridge structures. A comprehensive numerical simulation framework is developed using finite element analysis (FEA) to model the dynamic interactions between blast waves and the masonry materials. Key parameters, including the blast load intensity, duration, and distance from the blast source, are varied to assess their impact on bridge performance. The results reveal significant insights into the deformation patterns, stress distribution, and potential failure modes of masonry bridges under blast loading scenarios. The findings underscore the importance of incorporating blast resistance measures in the design and retrofitting of masonry bridges to enhance their resilience against explosive events. This study contributes to the advancement of safety standards and design guidelines for masonry bridge structures in the context of blast loading, providing valuable information for engineers, policymakers, and infrastructure managers. [ABSTRACT FROM AUTHOR]

This study investigates blast dynamics of prestressed segmented columns assembled of osteomorphic interlocking elastic blocks without any binding materials or mechanical connectors. The unique ability of the interlocking structures to absorb and dissipate energy through the independent movement of their segments is analyzed using the nonlinear finite element method. The effects of the number of blocks, the axial prestress, the friction, and the level of interlocking between the contact surfaces on the flexural response and energy absorption capability of the segmented column are investigated parametrically. It is demonstrated that the detachments between blocks control the energy absorption capability of these structures. Therefore, the number of blocks, the axial prestress, and the level of interlocking (i.e., the parameters influencing the available detachment between blocks) define the response of this column to blast loads. Columns segmented into a greater number of blocks with lower prestress levels exhibit a higher damping capability but reduced column stiffness, which is usually undesirable in structural applications. A higher level of interlocking between the contact surfaces of blocks increases the damping capacity of the column without reducing its stiffness. The effect of friction is found to be insignificant for all cases considered. The effect of interlocking is small relative to the effects of prestress and the number of blocks. However, it provides an independent design parameter for the passive mitigation of blast loads. [ABSTRACT FROM AUTHOR]

The nonlinear dynamic response of magnetoelectroelastic (MEE) functionally graded plates (MEEFG) subjected to blast loads and operating in a temperature environment is examined in this study. The goal of this research is to investigate the impact of pyrocoupling along with the blast loads on the coupled nonlinear behavior of smart MEEFG plates. The material properties of MEEFG plates are calculated using the well-known modified power law. The kinematics of the plate is supposed to follow Reddy's higher-order shear deformation theory (HSDT). Also, von-Karman's equations are used to bring nonlinearity into the model. The blast loads are calculated using an exponential function and are expected to be dispersed evenly across the plate's surface. The principle of virtual work is used to develop the governing equations using finite element (FE) methods, which is then solved using the direct iterative technique. The numerical examples are offered to show how gradient patterns, gradient index, and blast loading parameters affect the nonlinear dynamic response. [ABSTRACT FROM AUTHOR]

Recently, explosions, collisions, and fires have occurred frequently around the world due to terror attacks, and impact accidents. Particularly, since the 9.11 terror attack, public anxiety heightened due to lack of safety in our society. The incidents can be viewed as examples of possible extreme loading scenarios that can occur in structures and infrastructures. Among all of structures and infrastructures, prestressed concrete containment vessels (PCCVs) are the most vulnerable structures from terrors and accidents. Therefore, in this study, finite element software LS-DYNA and MIDAS FEA, are used to evaluate of PCCVs applied with blast induced fire loading resistance. Since the blast test on a full-scale PCCV is not realistically possible, it is necessary to develop a precise simulation tool to accurately evaluate the damage level of a full-scale PCCV. This study aims to improve the accuracy of the simulation tool by calibrating numerical software using experimental test data. Then, the parametric study is conducted according to the explosive charge weight, standoff distance, and concrete compressive strength of a PCCV using calibrated blast and fire simulation tools. Based on the study results, the level of damage assessment to PCCVs applied with blast-fire loading can be precisely evaluated. [ABSTRACT FROM AUTHOR]

The ductility of a column is one of the most important characteristics of a structure subjected to unexpected overloads, load reversals, blast loads or dynamic impacts. Structural ductile members are capable of dissipating large amounts of energy by undergoing large deformations before failure, hence providing early warning to the occupants of the building. Previous analyses conducted by the authors suggest that, in addition to the type of column (steel, reinforced concrete and composite steel–concrete), the applied measure of ductility as well as other factors (the materials used and the loading and boundary conditions) have a significant influence on a column’s ductility. This paper proposes a new approach to the analysis of the ductility of columns. This approach distinguishes between the column’s pre-peak, post-peak and total ductility, and develops ductility parameters based on the displacement and energy for each of these ductility types. Based on experimental and numerical research on two-chord composite steel–concrete columns subjected to vertical monotonic loads, the influence of concrete strength and batten plate spacing on the columns’ vertical ductility is evaluated. It is concluded that designing two-chord composite steel–concrete columns to have small batten plate spacing and a relatively low concrete strength class can maximise the vertical ductility. [ABSTRACT FROM PUBLISHER]

This paper describes a conservative analytical approach for quantification of glazing hazard in terms of number of casualties among building occupiers from flying glass fragments produced by shattered windows due to external explosive blast. Three main stages are discussed in the proposed analytical approach: modelling nonlinear transient–dynamic response of monolithic windows subjected to conventional explosions, conservative estimation of glass fragment trajectories influenced by additional aerodynamic forces due to vented blast pressures and estimation of casualties. Four injury severity levels are considered, ranging from minor cuts and bruises to multiple serious injuries with significant blood loss. The total kinetic energy of fragments at impact on occupiers is estimated and used to predict the severity level of injuries, with calculation based on available injury data from archive events. Comparison studies presented in this paper highlight the lack of robustness of existing methods towards quantification of glazing hazard due to explosive blasts. The proposed analytical method will be of direct importance to both engineers and practitioners involved with planning glazing retrofits for existing buildings and identifying cost-effective combinations of protection measures for new buildings. [ABSTRACT FROM PUBLISHER]