Improving anti-progressive collapse capacity of welded connection based on energy dissipation cover-plates

The purpose of this study is to enable emergency recovery of damage caused by earthquakes in structures and prevent secondary damage by controlling progressive collapse. Although there have been many previous studies using reinforcing bars and meshes, there have been few studies using carbon grid fibers as a substitute for tension members. This study aims to quantitatively present disaster response seismic performance by manufacturing concrete panels with no layers, one layer, or two layers of carbon fiber grids inserted and to compare the flexural strength and energy dissipation capacity. Flexural strength increased by 7% with one layer and 15% with two layers compared with no layer. Energy dissipation capacity increased by 30 times with one layer and by 56 times with two layers compared with no layers, and showed great improvement in terms of seismic performance. Especially because of the large increase in the energy dissipation capacity, the carbon fiber grid reinforcement method is considered to be an effective method for improving seismic performance.

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Impact behaviour of freeze-dried and fresh pomelo ( Citrus maxima ) peel: influence of the hydration state

Royal Society Open Science ◽

10.1098/rsos.140322 ◽

2015 ◽

Vol 2 (6) ◽

pp. 140322 ◽

Cited By ~ 10

Author(s):

Marc Thielen ◽

Thomas Speck ◽

Robin Seidel

Keyword(s):

Energy Dissipation ◽

Freeze Drying ◽

Progressive Collapse ◽

Maxwell Model ◽

Relative Energy ◽

Point Of View ◽

Freeze Dried ◽

Transmitted Force ◽

Citrus Maxima ◽

Energy Dissipation Capacity

Pomelos ( Citrus maxima ) are known for their thick peel which—inter alia—serves as energy dissipator when fruits impact on the ground after being shed. It protects the fruit from splitting open and thus enables the contained seeds to stay germinable and to potentially be dispersed by animal vectors. The main part of the peel consists of a parenchymatous tissue that can be interpreted from a materials point of view as open pored foam whose struts are pressurized and filled with liquid. In order to investigate the influence of the water content on the energy dissipation capacity, drop weight tests were conducted with fresh and with freeze-dried peel samples. Based on the coefficient of restitution it was found that freeze-drying markedly reduces the relative energy dissipation capacity of the peel. Measuring the transmitted force during impact furthermore indicated a transition from a uniform collapse of the foam-like tissue to a progressive collapse due to water extraction. Representing the peel by a Maxwell model illustrates that freeze-drying not only drastically reduces the damping function of the dashpots but also stiffens the springs of the model.

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Progressive collapse of building structures

AccessScience ◽

10.1036/1097-8542.yb090023 ◽

2015 ◽

Keyword(s):

Progressive Collapse ◽

Building Structures

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Energy dissipation across the front of shock wave in rheological materials filled with second phase inclusions

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2006134135 ◽

2006 ◽

Vol 134 ◽

pp. 883-887

Author(s):

Jian-kang Chen ◽

Jue Zhu

Keyword(s):

Shock Wave ◽

Energy Dissipation ◽

Second Phase

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Calculation And Experimental Substantiation Of Optimal Design Of The Welded Joint Of Plates On Соver Plates

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2020.03.17-24 ◽

2020 ◽

pp. 17-24

Keyword(s):

Welded Joint ◽

Experimental Studies ◽

Engineering Calculation ◽

Tensile Tests ◽

Physical Nonlinearity ◽

Steel Plates ◽

Optimal Parameters ◽

Actual Problem ◽

Numerical Research ◽

Cover Plates

The article is devoted to the actual problem of assigning optimal parameters for connecting steel plates on cover plates with angular welds that are widely used in construction practice. The article presents the results of a comprehensive study of operation of a welded assembly of the plates connection on cover plates. An algorithm is proposed for determining the optimal parameters of a welded joint with fillet welds on the cover plates, which makes it possible to obtain a strength balanced connection. The results of full-scale tensile tests of models were presented. These results confirmed the correctness of the assumed design assumptions, and made it possible to obtain a form of destruction, not characteristic and not described in the normative literature, expressed by cutting the main elements along the length of the overlap in the joint. The possibility of such a form of destruction was confirmed by the results of numerical research in a nonlinear formulation. The optimal parameters of the nodal welded joint determined by engineering calculation are confirmed by experimental studies, as well as by the results of numerical experiments on models of calculation schemes, taking into account the physical nonlinearity of the material operation. The obtained dependence for determining the bearing capacity of the joint by the cut-off mechanism and the expression for limiting the overlap length of the cover plates will make it possible to predict the nature of the fracture and design equally strong joints.

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Protection of buildings and structures against progressive collapse within the framework of legislative and regulatory requirements

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.02.46-54 ◽

2019 ◽

pp. 46-54 ◽

Cited By ~ 1

Keyword(s):

Progressive Collapse ◽

Professional Community ◽

Regulatory Requirements ◽

Technical Regulation ◽

Regulatory Documents ◽

Common Position ◽

Local Destruction

At present, the current legislative and regulatory documents do not contain a clear and unambiguous answer to the question, what buildings and structures should be designed resistant to progressive collapse. In this regard, the analysis of the legal and regulatory requirements of the need for calculations to prevent the progressive collapse of buildings and structures due to hypothetical or suspected local destruction is presented. The main legislative requirements of technical regulation in the field of ensuring the mechanical safety of buildings and structures, as well as the requirements of regulatory documents regarding the design of the protection of building and structures against progressive collapse are considered. The analysis of the fundamental principles features of the calculation for the structural protection against progressive collapse is given. Some issues discussed by the professional community in the direction of possible ways of solving the actual problems of the presented problem are considered. The conclusion is made about the need for further dialogue of the professional community on the development of a common position on the protection of buildings and structures from progressive collapse, which should be reflected in the legislative and regulatory requirements.

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