Evaluation of perforated steel plates as connection in glulam–concrete composite structures

2012 ◽  
Vol 28 (1) ◽  
pp. 216-223 ◽  
Author(s):  
José Luiz Miotto ◽  
Antonio Alves Dias
2018 ◽  
Vol 58 (11) ◽  
pp. 2133-2141 ◽  
Author(s):  
Ying Qin ◽  
Er-Feng Du ◽  
Yong-Wei Li ◽  
Jing-Chen Zhang

2019 ◽  
Vol 56 (2) ◽  
pp. 460-465 ◽  
Author(s):  
Victor Geanta ◽  
Ionelia Voiculescu ◽  
Tudor Chereches ◽  
Teodora Zecheru ◽  
Liviu Matache ◽  
...  

The explosive effect and high velocity penetration of the ballistic projectiles of various sizes, design and compositions, on impact with different targets (armors composed of a combination of different metals) are complex. Both practical experiments and mathematical modeling of the phenomena associated to the interaction projectile-target are required to estimate their effect or to design more efficient projectiles and armor. In this study, the basic element of the simulation model is an incendiary projectile of caliber 7.62 mm with medium piercing power, launched with a maximum speed of 750 ms-1 on the multi-material target, which contains 4 different layers assembled into a ballistic cassette made of aluminum. The purpose of this ballistic cassette is to ensure a better contact and handling of multi-layer materials. The proposed model was calculated using mathematical modeling and empirical material constants to describe the nonlinear transitory impact process. Mathematical simulation of the impact between the projectile and target during impact shows that the projectile moves sequentially through the ballistic package, causing perforation, plastic deformation and heating, the resulting fragments being then expelled into the space around the target. The model indicates that the projectile will penetrate the front aluminum plate, as well as the AlCrFeCoNi and steel plates, but will be stopped by the aluminum backing plate. The real impact tests carried out using the ballistic cassette at dynamic impact with the 7.62mm incendiary projectile confirm the model assumptions, which prove the capacity of the composite model to safely stop the projectile.


2021 ◽  
Vol 71 (1) ◽  
pp. 87-93
Author(s):  
Baris Şahiner ◽  
Sunullah Özbek ◽  
Tarik Baykara ◽  
Alpaslan Demirural

The detection of underwater objects is one of the most critical technologies, and there have been constant efforts for developing sophisticated sonar systems in naval warfare. Against such efforts, the countermeasure of hiding underwater vehicles, equipment and weapons is another technological challenge. One of the effective countermeasures against sonic detection for the submarines and other underwater objects, such as naval mines, is to employ composite/hybrid materials to prevent ease of detection. Geometrical forms, shapes and layers, along with the tuning of the acoustical impedance, lead to a considerable decrease of the sonar signals via absorption of the sonic waves. In this study, an original and novel design of multi-layered composite/hybrid structure was developed and underwater acoustic testing procedures of reflection, transmission and scattering were applied in 80 kHz100 kHz frequency range. The findings obtained in this study showed that the multi-layered composite/hybrid materials with porous structure possess much lower values in millivolt than steel plates and might be potential candidates as covering and/or casing materials for underwater mines to reduce the acoustical signature against detection and identification.


Author(s):  
Jin Huo ◽  
Zirong Hu ◽  
Yuping Sun

Concrete-filled steel structures (SC), or called steel concrete composite structures are composed of steel plates and reinforced concrete. This kind of structures has demonstrated more effective against blast and impact loads, and has been used in risk-sensitive structures such as the nuclear electric power plant and other critical constructions. The comprehensive modeling and analysis is performed in this paper for the full scale SC panel against aircraft impact after the testing results of 1/7.5 scaled model was reviewed and correlated. The methodology, modeling approach, and mesh density sensitivity investigation is presented.


Author(s):  
Larice Gomes Justino Miranda ◽  
Otávio Prates Aguiar ◽  
Paulo Estevão Carvalho Silvério ◽  
Rodrigo Barreto Caldas

Abstract Since the development of perforated plate shear connectors, different formulations have been proposed to predict their shear strength. Most of these formulations were derived from standard push-tests on multiple concrete filled holes (CFH) specimens simulating specific steel-concrete composite beam applications. Aiming at a more general application of these connectors in composite structures and the understanding of the physical and geometric parameters that influence their shear strength, the present work evaluated the use of 12 different formulations to predict 92 test results of single-hole specimens extracted from the literature. Such tests were chosen because the single-hole configuration allows better isolation of the connection behavior which facilitates comparative analysis. The predictions were statistically evaluated, and it was considered that the best formulations were those that showed lower scatter of data and a correction factor closer to one. Also, it was investigated if the individual terms that constitute the formulations adequately describe or show relation to the mechanics that govern the connection. It was verified that the best statistically rated formulations were also the ones showing clearer relation to the connector mechanical behavior. Among the evaluated formulations, three were significantly better than the others for strength prediction, however, it was noted that they can be further improved by considering the influence of concrete confinement and plate thickness on the hole’s strength.


2014 ◽  
Vol 893 ◽  
pp. 614-617
Author(s):  
Petr Agel ◽  
Antonín Lokaj

Timber-concrete composite structures, which use advantages of both materials, are suitable for new works and reconstructions of civil and residential buildings. There are described many methods of joining between timber beam and concrete slab in technical literature. Joints are more and more sophisticated which brings higher demands on work control and technology. Main goal of the paper is in design technologically low demanding method of joining with steel plates and nails, to test its shear strength and to compare it with other similar joining .


Author(s):  
Petr Agel ◽  
Antonín Lokaj

Abstract Timber-concrete composite structures which use advantages of both materials are suitable for new works and reconstructions of civil and residential buildings. There are described many methods of joining between timber beam and concrete slab in technical literature. Joints are more and more sophisticate which brings higher demands of work control and technology. Main goal of this paper is in design technologically low demanding method of joining with steel plates and nails, to test its shear strength and compare it with other similar joining method.


2014 ◽  
Vol 1020 ◽  
pp. 177-181
Author(s):  
Petr Agel ◽  
Antonin Lokaj

Timber-concrete composite structures, which use advantages of both materials, are suitable for new works and reconstructions of civil and residential buildings. There are described many methods of joining between timber beam and concrete slab in technical literature. Joints are more and more sophisticated which brings higher demands on work control and technology. Main goal of the paper is in design technologically low demanding method of joining with steel plates and nails, to test its shear strength and to compare it with other similar joining .


Author(s):  
Frances M. Ross ◽  
Peter C. Searson

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.


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