Search for SUSY in Final States with Z Bosons

A search for SUSY processes leading to final states with Z bosons is performed at a low mass point in the mSUGRA parameter space. The signature of such processes is studied using both a complete and a fast simulation. It is shown that the signal can be seen over the Standard Model background with high significance already at an integrated luminosity of 1fb^-1. The SUSY discovery potential is explored in the m_0,m_1/2 parameter space

Accurate and computationally efficient nonlinear static and dynamic analysis of reinforced concrete structures considering damage factors

Accurate nonlinear dynamic analysis of reinforced concrete structures is necessary for estimating the behavior of concrete structures during an earthquake. A realistic modeling approach to assess their strength and their ability to carry the expected seismic forces is of great importance. Although a number of constitutive models and modeling approaches have been proposed in order to capture the behavior of reinforced concrete structures under static loading conditions, only a few of these numerical models have been extended to dynamic problems.The objective of this paper is to integrate a computationally efficient 3D detailed modelling of concrete structures with damage factors that take into account the opening and closing of cracks, as well as, damage factors for steel reinforcement considering the surrounding concrete damage level, in order to capture the level of damage and stiffness degradation of structures undergoing many loading cycles.In the adopted numerical model, the concrete domain is discretized with 8-noded isoparametric hexahedral finite elements, which treat cracking with the smeared crack approach, while the steel reinforcement is modeled as embedded beam elements inside the hexahedral mesh. The validity of the proposed method is demonstrated by comparing the numerical response with the corresponding experimental results of various reinforced concrete structural members and structures. Based on the numerical investigation, it was found that the proposed integration of the damage factors with computationally efficient concrete and steel material models can efficiently predict both static and dynamic nonlinear behavior of concrete structures, with the ability to capture the complicated phenomenon of the pinching effect

Accurate and computationally efficient nonlinear static and dynamic analysis of reinforced concrete structures considering damage factors

Accurate nonlinear dynamic analysis of reinforced concrete structures is necessary for estimating the behavior of concrete structures during an earthquake. A realistic modeling approach to assess their strength and their ability to carry the expected seismic forces is of great importance. Although a number of constitutive models and modeling approaches have been proposed in order to capture the behavior of reinforced concrete structures under static loading conditions, only a few of these numerical models have been extended to dynamic problems.The objective of this paper is to integrate a computationally efficient 3D detailed modelling of concrete structures with damage factors that take into account the opening and closing of cracks, as well as, damage factors for steel reinforcement considering the surrounding concrete damage level, in order to capture the level of damage and stiffness degradation of structures undergoing many loading cycles.In the adopted numerical model, the concrete domain is discretized with 8-noded isoparametric hexahedral finite elements, which treat cracking with the smeared crack approach, while the steel reinforcement is modeled as embedded beam elements inside the hexahedral mesh. The validity of the proposed method is demonstrated by comparing the numerical response with the corresponding experimental results of various reinforced concrete structural members and structures. Based on the numerical investigation, it was found that the proposed integration of the damage factors with computationally efficient concrete and steel material models can efficiently predict both static and dynamic nonlinear behavior of concrete structures, with the ability to capture the complicated phenomenon of the pinching effect

Accumulated Damage In Nonlinear Cyclic Static And Dynamic Analysis Of Reinforced Concrete Structures Through 3D Detailed Modeling

Accurate nonlinear cyclic static and dynamic analysis of reinforced concrete structures is necessary when trying to capture the behavior of concrete structures during earthquake excitations. The development of an objective and robust 3D constitutive modeling approach that will be able to account for the accumulated material damage during the cyclic loading of concrete structures is of great importance in order to realistically describe the physical failure mechanisms [1]. The proposed method is based on the experimental results and the concrete modelling of Kotsovos and Pavlovic [2] as modified by Markou and Papadrakakis [3]. The objective of this research work is to propose a computationally efficient modeling method that accounts for the accumulated damage developed in both concrete and steel materials during cyclic static and dynamic excitations.Two new damage factors are proposed herein that take into account the number of openings and closures of cracks during the nonlinear cyclic analysis, thus provide with the ability to account for the accumulated damage in both steel and concrete materials. Furthermore, a solution strategy that describes the behavior of concrete during the cyclic static and dynamic analysis is also presented.The proposed numerical method is validated by comparing its numerical response with the corresponding experimental data of a beam-column frame joint and a two-storey reinforced concrete frame, which were tested under cyclic static and dynamic loading conditions, respectively. Based on the numerical findings, the proposed algorithm manages to accurately capture the experimental results, while the simulation of the understudy models was performed with computational robustness and efficiency. This numerical outcome demonstrates the potential of the proposed 3D detailed modeling approach to be implemented for the seismic assessment of full-scale reinforced concrete structures through nonlinear cyclic static and dynamic analysis

Accumulated Damage In Nonlinear Cyclic Static And Dynamic Analysis Of Reinforced Concrete Structures Through 3D Detailed Modeling

Accurate nonlinear cyclic static and dynamic analysis of reinforced concrete structures is necessary when trying to capture the behavior of concrete structures during earthquake excitations. The development of an objective and robust 3D constitutive modeling approach that will be able to account for the accumulated material damage during the cyclic loading of concrete structures is of great importance in order to realistically describe the physical failure mechanisms [1]. The proposed method is based on the experimental results and the concrete modelling of Kotsovos and Pavlovic [2] as modified by Markou and Papadrakakis [3]. The objective of this research work is to propose a computationally efficient modeling method that accounts for the accumulated damage developed in both concrete and steel materials during cyclic static and dynamic excitations.Two new damage factors are proposed herein that take into account the number of openings and closures of cracks during the nonlinear cyclic analysis, thus provide with the ability to account for the accumulated damage in both steel and concrete materials. Furthermore, a solution strategy that describes the behavior of concrete during the cyclic static and dynamic analysis is also presented.The proposed numerical method is validated by comparing its numerical response with the corresponding experimental data of a beam-column frame joint and a two-storey reinforced concrete frame, which were tested under cyclic static and dynamic loading conditions, respectively. Based on the numerical findings, the proposed algorithm manages to accurately capture the experimental results, while the simulation of the understudy models was performed with computational robustness and efficiency. This numerical outcome demonstrates the potential of the proposed 3D detailed modeling approach to be implemented for the seismic assessment of full-scale reinforced concrete structures through nonlinear cyclic static and dynamic analysis

Computationally Efficient and Robust Nonlinear 3D Cyclic Modeling of RC Structures Through a Hybrid Finite Element Model (HYMOD)

A computationally efficient and robust simulation method is presented in this work, for the cyclic modeling of reinforced concrete (RC) structures. The proposed hybrid modeling (HYMOD) approach alleviates numerical limitations regarding the excessive computational cost during the cyclic analysis and provides a tool for the detailed simulation of the 3D cyclic nonlinear behavior of full-scale RC structures. The simplified HYMOD approach is integrated in this work with a computationally efficient cyclic concrete material model so as to investigate its numerical performance under extreme cyclic loading conditions. The proposed approach adopts a hybrid modeling concept that combines hexahedral and beam-column finite elements (FEs), in which the coupling between them is achieved through the implementation of kinematic constraints. A parametric investigation is performed through the use of the Del Toro Rivera frame joint and two RC frames with a shear wall. The proposed modeling method managed to decrease the computational cost in all numerical tests performed in this work, while it induced additional numerical stability during the cyclic analysis, in which the required number of internal iterations per displacement increment was found to be always smaller compared with the unreduced (hexahedral) model. The HYMOD provides for the first time with the required 3D detailed FE solution tools in order to simulate the nonlinear cyclic response of full-scale RC structures without hindering the numerical accuracy of the derived model nor the need of developing computationally expensive models that practically cannot be solved through the use of standard computer systems

DESIGN AND IMPLEMENTATION OF THE MOBILE GRID RESOURCE MANAGEMENT SYSTEM

We present a design of a Mobile Grid Resource Management System aimed at integrating mobile resources to an existing Grid infrastructure, while creating a platform for interoperability with telecommunications providers. In order to reduce the load on an existing infrastructure, we separate responsibilities and run additional features on mobile resources. Finally we present the Ikaros-EG implementation, IkarosM android application and the mobile-Grid concept.The system used for our implementation was the NCSR “Demokritos” ZEUS computer Cluster, where the Ikaros-EG framework consisting of a meta-data collector and the Ikaros-EG plug-in has been installed. The ZEUS cluster has local and Grid access to data and meta-data from numerous scientific experiments. Our objective was to incorporate the mobile resources using the NCSR Demokritos campus wireless infrastructure in order to run applications concerning accounting, statistics, or further data/meta-data formatting

Accurate and computationally efficient nonlinear static and dynamic analysis of reinforced concrete structures considering damage factors

Accurate nonlinear dynamic analysis of reinforced concrete structures is necessary for estimating the behavior of concrete structures during an earthquake. A realistic modeling approach to assess their strength and their ability to carry the expected seismic forces is of great importance. Although a number of constitutive models and modeling approaches have been proposed in order to capture the behavior of reinforced concrete structures under static loading conditions, only a few of these numerical models have been extended to dynamic problems. The objective of this paper is to integrate a computationally efficient 3D detailed modelling of concrete structures with damage factors that take into account the opening and closing of cracks, as well as, damage factors for steel reinforcement considering the surrounding concrete damage level, in order to capture the level of damage and stiffness degradation of structures undergoing many loading cycles. In the adopted numerical model, the concrete domain is discretized with 8-noded isoparametric hexahedral finite elements, which treat cracking with the smeared crack approach, while the steel reinforcement is modeled as embedded beam elements inside the hexahedral mesh. The validity of the proposed method is demonstrated by comparing the numerical response with the corresponding experimental results of various reinforced concrete structural members and structures. Based on the numerical investigation, it was found that the proposed integration of the damage factors with computationally efficient concrete and steel material models can efficiently predict both static and dynamic nonlinear behavior of concrete structures, with the ability to capture the complicated phenomenon of the pinching effect.The European Research Council Advanced Grant “MASTER-Mastering the computational challenges in numerical modeling and optimum design of CNT reinforced composites” (ERC-2011-ADG 20110209).http://www.elsevier.com/locate/engstruct2020-01-01hj2019Civil Engineerin

A new damage factor for seismic assessment of deficient bare and FRP-retrofitted RC structures

The seismic assessment of reinforced concrete (RC) structures before and after retrofitting is a challenging task, mainly because existing numerical tools cannot accurately model the evolution of concrete damage. This article proposes an innovative numerical method suitable to model and assess the ultimate carrying capacity of RC structures. The modelling approach proposes a steel constitutive material model with a damage factor that accounts for accumulated damage within the surrounding concrete domain, which effectively captures bar slippage. The proposed method is validated with experimental results from full-scale cyclic tests on deficient bare and CFRP-retrofitted RC joints tested previously by the authors. The results indicate that the proposed simulation method captures the extreme nonlinearities observed in the tested RC joints, with acceptable accuracy and computational robustness. The results of this study are expected to contribute towards the development of more reliable numerical tools and design guidelines for efficient seismic assessment of RC structures before and after earthquakes