scholarly journals Structural performance of hybrid sandwich slabs under shear loading

2017 ◽  
Vol 21 (3) ◽  
pp. 809-837 ◽  
Author(s):  
Mohammad Mastali ◽  
Joaquim Barros ◽  
Isabel Valente
Keyword(s):  
Load Capacity ◽  
Sandwich Panels ◽  
Shear Loading ◽  
Structural Performance ◽  
Special Focus ◽  
Shear Span ◽  
Shear Connectors ◽  
Shear Connection ◽  
Glass Fiber Reinforced ◽  
High Load Capacity

In a hybrid panel with glass fiber-reinforced polymer (GFRP) bottom skin and ribs, and deflection hardening cementitious composites (DHCC) top layer, it is very important to provide good shear connection between these various components in order to increase the load carrying capacity of the resulting hybrid slabs and a larger increment of deflection before the occurrence of the structural softening of this panel. The effectiveness of the proposed hybrid sandwich panels strongly depends on the performance of the shear connectors. The efficiency of indented shear connectors in improving the flexural performance of hybrid sandwich panels is here demonstrated. Since the efficiency of indented shear connectors in the hybrid sandwich panels is unknown, efforts are made in this paper in investigating the shear performance of hybrid slabs. A special focus is given on the indented shear connector’s behavior, considering different shear span ratios in ranges of 2.00, 1.39, and 0.77. In this regard, six hybrid sandwich panels were manufactured and experimentally tested under different shear loads. Then, the results are interpreted comprehensively. The results obtained show that the GFRP rib thickness and height, and shear span ratios influence the damage events and the structural performance of the hybrid sandwich panels. Moreover, it was observed that using indented shear connectors in the hybrid slabs, regardless of the shear span ratios, provides high load capacity, high stiffness, and large residual deflection.

scholarly journals Thermal Resistance of Insulated Precast Concrete Sandwich Panels

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Sani Mohammed Bida ◽  
Farah Nora Aznieta Abdul Aziz ◽  
Mohd Saleh Jaafar ◽  
Farzad Hejazi ◽  
Nabilah Abu Bakar
Keyword(s):  
Thermal Resistance ◽  
Alternative Energy ◽  
Precast Concrete ◽  
Sandwich Panels ◽  
Green Building ◽  
Control Panel ◽  
Shear Connectors ◽  
Shear Connection ◽  
Concrete Layer ◽  
Structural Applications

AbstractMany nations are already working toward full implementation of energy efficiency in buildings known as Green Building. In line with this perspective, this paper aims to develop a thermally efficient precast concrete sandwich panels (PCSP) for structural applications. Therefore, an experimental investigation was carried out to determine the thermal resistance of the proposed PCSP using Hotbox method and the results were validated using finite element method (FEM) in COMSOL Multiphysics Software. The PCSP were designed with staggered shear connectors to avoid thermal bridges between the successive layers. The staggered connectors are spaced at 200 mm, 300 mm and 400 mm on each concrete layer, while the control panel is designed with 200 mm direct shear connection. In the experimental test, four (4) panels of 500 mm × 500 mm and 150 mm thick were subjected to Hotbox Test to determine the thermal resistance. The result shows that thermal resistance of the PCSP with staggered shear connection increases with increase in spacing. The PCSP with 400 mm staggered shear connectors indicates the best thermal efficiency with a thermal resistance (R value) of 2.48 m2K/W. The thermal performance was verified by FEA which shows less than 5% error coupled with a precise prediction of surface temperature gradient. This indicates that, with conventional materials, thermal path approach can be used to develop a precast concrete building with better thermal resistant properties. Hopefully, stakeholders in the green building industry would find this proposed PCSP as an alternative energy efficient load bearing panel towards sustainable and greener buildings.

scholarly journals Experimental Study of Structural Performance of Precast Concrete Insulated Sandwich Panels with Cruciform Cross Section GFRP Connectors

2019 ◽  
Vol 303 ◽  
pp. 01004
Author(s):  
Xiaohong Yang ◽  
Yu Jiang ◽  
Huyue Sun ◽  
Zhenghua Sun
Keyword(s):  
Cross Section ◽  
Precast Concrete ◽  
Sandwich Panels ◽  
Fiber Reinforced Polymer ◽  
Structural Performance ◽  
Shear Tests ◽  
Reinforced Polymer ◽  
Tension Load ◽  
Glass Fiber Reinforced ◽  
Ultimate Tension Load

This study investigated the structural performance of precast concrete insulated sandwich panels with cruciform cross section glass fiber-reinforced polymer (GFRP) connectors, based on tensile and shear tests. 5 tensile specimens and 4 shear specimens were fabricated and tested. The load-displacement relation and failure mode of the specimens were analyzed. The results revealed that the average ultimate tension load of the tested specimens with single GFRP connector was 13.14kN with concrete splitting or concrete partial cone failure. For the shear specimens, the average ultimate shear load was 14.83kN with rupture failure of GFRP connector. Furthermore, durability of sandwich panels was investigated, by fabricating and testing 48 tensile specimens with GFRP connectors immersed in tension load had sufficient safety in different design situations.

scholarly journals Development of Shear Connections in Steelconcrete Composite Structures

2015 ◽  
Vol 15 (4) ◽  
pp. 23-32 ◽  
Author(s):  
Antoni Biegus ◽  
Wojciech Lorenc
Keyword(s):  
Composite Structures ◽  
Basic Research ◽  
Special Focus ◽  
Shear Connectors ◽  
Shear Connection ◽  
Shear Connections ◽  
Continuous Shear ◽  
Modelling Techniques ◽  
Year 2000 ◽  
Modern Solution

Abstract Different types of shear connectors and modelling techniques are presented. Basic research conducted or presented after year 2000 is taken into consideration, following the idea of concrete dowel implemented in the form of perfobond strip at the beginning of the 1980s by F. Leonhardt. The latest research in the field of continuous shear connectors applied in bridges is highlited with special focus at the composite dowel shear connection, as it seems to be the most modern solution being strongly introduced to the industry. Final shape of composite dowel shear connection is presented.

Direct Shear Responses of Insulated Concrete Sandwich Panels with GFRP Shear Connectors

2012 ◽  
Vol 204-208 ◽  
pp. 803-806 ◽  
Author(s):  
Hyun Do Yun ◽  
Seok Joon Jang ◽  
Young Chan You
Keyword(s):  
Shear Flow ◽  
Failure Modes ◽  
High Surface ◽  
Sandwich Panels ◽  
Shear Connector ◽  
Concrete Wall ◽  
Flow Strength ◽  
Concrete Walls ◽  
Shear Connectors ◽  
Glass Fiber Reinforced

This paper investigates shear flow strength of insulated concrete sandwich panels with glass fiber reinforced polymer (GFRP) shear connectors based on push-out test. The precast insulated concrete panels consist of 60mm concrete wall, 100mm insulation, and 130mm concrete wall. Two concrete walls were connected with GFRP corrugated shear connector. Four specimens with variables such as the insulation type and the width of GFRP corrugated shear connector were made. Failure modes, shear flow-deflection relationships and post-peak strength were investigated. Test results indicate that the specimens with EPS insulation show higher shear flow strength than those with XPSS insulation due to the relatively high surface roughness of EPS insulation, and the shear flow strength increased with increasing shear connector width.

FIRE RESISTACE OF SHEAR CONNECTORS FOR COMPOSITE BEAMS

2020 ◽  
Vol 92 (6) ◽  
pp. 59-65
Author(s):  
G.P. TONKIH ◽  
◽  
D.A. CHESNOKOV ◽  
◽  
Keyword(s):  
Fire Resistance ◽  
Composite Structure ◽  
Composite Structures ◽  
Composite Beams ◽  
Design Codes ◽  
Connection Strength ◽  
Shear Connectors ◽  
Shear Connection ◽  
Capacity Reduction ◽  
Russian Research

Most of Russian research about composite structure fire resistance are dedicated to the composite slab behavior. The composite beams fire resistance had been never investigated in enough volume: the temperature evaluation within the scope of the actual Russian design codes leads to the significant reduction in the shear connection strength. Meanwhile, there no correlation between the strength decreasing and type of the shear connection. The article provides an overview of the relevant researches and offers some approaches which could take into account bearing capacity reduction of the shear connectors within composite structures design.

Influence of Insulation Type on In-Plane Shear Behavior of Insulated Concrete Sandwich Panels (ICSP) with GFRP Grid Shear Connectors

2014 ◽  
Vol 525 ◽  
pp. 416-419 ◽  
Author(s):  
Hye Ran Kim ◽  
Dae Hyun Kang ◽  
Hyun Do Yun
Keyword(s):  
Shear Flow ◽  
Outer Wall ◽  
Expanded Polystyrene ◽  
Test Results ◽  
Flow Strength ◽  
Plane Shear ◽  
Shear Connectors ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Shear Performance

This paper reports the experimental results to evaluate in-plane shear performance of insulated concrete sandwich panel (ICSP) with glass fiber-reinforced polymer (GFRP) grid shear connectors. The variables considered in this study are the grid size (35 and 53mm) of GFRP shear connectors and the types of insulation (expanded polystyrene, EPS and extruded polystyrene with special slots, XPSS). For loading in-plane shear force to interface between inner and outer wall of ICSP system, the ICSP specimens were supported vertically at the bottom edge of the two concrete outer walls by steel blocks. The test results indicate that ICSP with XPSS developed higher shear flow strengths in ICSP with EPS when 35mm spacing of GFRP grid is used. Also, the test results indicated that as the grid spacing of GFRP shear connector decreases, the shear flow strength of ICSP with XPSS insulation was higher, but the shear flow strength of ICSP with EPS insulation was lower.

Experimental analysis of the automated process of sanding aircraft surfaces

2014 ◽  
Vol 118 (1199) ◽  
pp. 53-64
Author(s):  
B. Giublin ◽  
J. A. Vieira ◽  
T. G. Vieira ◽  
L. G. Trabasso ◽  
C. A. Martins
Keyword(s):  
Load Capacity ◽  
Manufacturing Processes ◽  
Robotic Cell ◽  
Research Project ◽  
Average Value ◽  
Aluminum Metal ◽  
Structural Assembly ◽  
Riveting Process ◽  
High Load Capacity ◽  
Operating Method

Abstract ITA and EMBRAER are currently executing the research project Automation of Aircraft Structural Assembly (AASA) whose goal is to implement a robotic cell for automating the riveting process of aeronautical structures. The proposal described herein complements the AASA project, adds other manufacturing processes, namely sanding and polishing of aircraft surfaces. To implement the additional processes AASA project resources and facilities were used (robots and metrology systems) and devices designed and /or acquired to allow sharing of these resources. Among these, an Automatic Tooling Support for AERonautics structures (ATS_AER) was designed and built; also, a robot tool changer with high load capacity was acquired. The outcome of this research project is the evaluation of the feasibility of automating the processes of sanding and polishing metal surfaces in the aircraft manufacture using robots. The operating method adopted for surface treatment employed the ‘U’ type trajectory optimised to be run by a KUKA robot KR 500. The sanding process has been applied to aluminum metal sheet specimen sized 2•18ft2 (0•20m2) and used commercial 600 and 800 sandpaper. The automated sanding process yielded an average value of RA 0•48 ± 0•08 which is 25% more efficient when compared to the traditional, manual process whose average value of RA is 0•75 ± 0•51.

Static Performance of a Hydrostatic Thrust Foil Bearing for Large Scale Oil-Free Turbomachines

2020 ◽  
Author(s):  
Nguyen LaTray ◽  
Daejong Kim ◽  
Myongsok Song
Keyword(s):  
Large Scale ◽  
Load Capacity ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Outer Diameter ◽  
Frictional Loss ◽  
Foil Bearing ◽  
Foundation Model ◽  
Static Performance ◽  
High Load Capacity

Abstract This work presents a novel design of a hydrostatic thrust foil bearing (HSTFB) with an outer diameter of 154mm along with simulation and test results up to specific load capacity of 223kPa (32.3psi). The HSTFB incorporates a high pressure air/gas injection to the thrust foil bearing with a uniform clearance. This bearing has high load capacity, low power loss, and no friction/wear during startup and shutdown. In addition, the HSTFB allows for bidirectional operation. The paper also presents an advanced simulation model which adopts the exact locations of a tangentially arranged bumps to a cylindrical two-dimensional plate model of the top foil. This method predicts top foil deflection with better accuracy than the traditional independent elastic foundation model which distributes the bump locations over the nodal points in the cylindrical coordinates, and with less computational resource than the finite element method applied to the entire bump/top foils. The presented HSTFB, was designed for Organic Rankine Cycle (ORC) generators, but its performance was predicted and measured using air in this paper. The bearing static performance is compared analytically against the rigid counterpart, and presented at different supply pressures, speeds, and minimum film thicknesses. Experimental verification is conducted at 10, 15 and 20krpm. The measured load capacity and frictional loss agree well with the prediction. The measured film thickness also agrees with the prediction after the structural deflection of the thrust runner disc is compensated. Overall, the novel HSTFB demonstrates an excellent static performance and shows good potential for adoption to the intended ORC generators and other large oil-free turbomachines.

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