Partial Gaussian-Approximation Soft Demapper for the Core Layer of MIMO-LDM in ATSC 3.0

The effect of initial waviness on the wrinkling of faces in sandwich construction is studied. Formulae are derived to determine the failing stress when the faces wrinkle due to failure of the core in tension, compression or shear. The importance of core strength requirements in maintaining surface smoothness is noted. A comparison of theory with experiments is made, and the agreement between the two is found to be reasonably good.A sandwich construction consists of two thin face layers of high-strength material and a thick core layer of lightweight material. The function of the core is twofold. Firstly, it increases the bending rigidity of the faces and second, it stabilises them so that they will not wrinkle until high stress is reached.

Download Full-text

Free Vibration Analysis of Symmetric Sandwich Beams

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.872.399 ◽

2017 ◽

Vol 872 ◽

pp. 399-404

Author(s):

Zakaria Ibnorachid ◽

Khalid El Bikri ◽

Lhoucine Boutahar

Keyword(s):

Sandwich Beam ◽

Free Vibration Analysis ◽

Core Layer ◽

Equation Of Motion ◽

Geometrical Parameters ◽

Symmetric Vibration ◽

Materials Properties ◽

The Core ◽

Validation Of Results ◽

Good Agreement

The aim of the present work is to study the linear free symmetric vibration of three-layer sandwich beam using the energy method. The zigzag model is used to describe the displacement field. The theoretical model is based on the top and bottom layers behave as Euler-Bernoulli beams while the core layer as a Timoshenko beam. Based on Hamilton’s principle, the governing equation of motion sandwich beam is obtained in order to calculate the linear frequency parameters. Two types of boundary conditions simple supported-simple-supported (SS-SS) and clamped-clamped (C-C) under the influence of materials properties and geometrical parameters are studied. The validation of results is done by comparing with another studies, which available in the literature and found good agreement between the studies.

Download Full-text

An attempt to use „Tetra Pak” waste material in particleboard technology

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0015.2376 ◽

2021 ◽

Vol 114 ◽

pp. 70-75

Author(s):

Radosław Auriga ◽

Piotr Borysiuk ◽

Alicja Auriga

Keyword(s):

Mechanical Properties ◽

Water Absorption ◽

Bending Strength ◽

Physical And Mechanical Properties ◽

Core Layer ◽

Waste Material ◽

Thickness Swelling ◽

The Core ◽

Tetra Pak ◽

The Impact

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.

Download Full-text

PERFORMANCE OF CONNECTED PRECAST LIGHTWEIGHT SANDWICH FOAMED CONCRETE PANEL UNDER FLEXURAL LOAD

Jurnal Teknologi ◽

10.11113/jt.v75.5244 ◽

2015 ◽

Vol 75 (9) ◽

Author(s):

Noridah Mohamad ◽

Abdul Aziz Abdul Samad ◽

Noorwirdawati Ali ◽

Josef Hadipramana ◽

Norwati Jamaluddin

Keyword(s):

Failure Modes ◽

Ultimate Load ◽

Core Layer ◽

Crack Pattern ◽

Control Panel ◽

Structural Behaviour ◽

The Core ◽

Steel Bar ◽

Mode Of Failure ◽

Foamed Concrete

This paper investigates the structural behaviour of two connected Sandwiched Precast Lightweight Foamed Concrete Panel (PLFP) in term of their load bearing capacities and failure modes. Three (3) connected PLFP panels were cast using foamed concrete as the wythe and polystyrene as the core layer. Each connected panel were cast from two single panels connected using L-bar connection. The panels were strengthened with steel bar reinforcement embedded in both wythes which were connected to each other by the steel shear truss connectors. The connected PLFP panels were tested under flexural load. A single PLFP panel was cast as a control panel and tested under axial load. The results were analysed in term of the panel’s ultimate load, crack pattern and mode of failure. Results showed that the two connected PLFP panels were able to sustain slightly lower ultimate load compared to single PLFP panel. Crack at 45 degree angle at top half of panel and small crack at surface between joint of the connection were observed.

Download Full-text

Spatio-Temporal Change Characteristics of Spatial-Interaction Networks: Case Study within the Sixth Ring Road of Beijing, China

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi8060273 ◽

2019 ◽

Vol 8 (6) ◽

pp. 273 ◽

Cited By ~ 4

Author(s):

Jing Yang ◽

Disheng Yi ◽

Bowen Qiao ◽

Jing Zhang

Keyword(s):

Urban Areas ◽

Traffic Management ◽

Spatial Interaction ◽

Small World ◽

Core Layer ◽

Vital Role ◽

Interaction Networks ◽

Ring Road ◽

The Core ◽

Spatio Temporal

Spatial-interaction networks are an important factor in geography that could help in the exploration of both human spatial-temporal behavior and the structure of urban areas. This paper analyzes changes in the spatio-temporal characteristics of the Spatial-Interaction Networks of Beijing (SINB) in three consecutive steps. To begin with, we constructed 24 sequential snapshots of spatial population interactions on the basis of points of interest (POIs) collected from Dianping.com and various taxi GPS data in Beijing. Then, we used Jensen–Shannon distance and hierarchical clustering to integrate the 24 sequential network snapshots into four clusters. Finally, we improved the weighted k-core decomposition method by combining the complex network method and weighted distance in a geographic space. The results showed: (1) There are three layers in the SINB: a core layer, a bridge layer, and a periphery layer. The number of places greatly varies, and the SINB show an obvious hierarchical structure at different periods. The core layer contains fewer places that are between the Second and Fifth Ring Road in Beijing. Moreover, spatial distribution of places in the bridge layer is always in the same location as that of the core layer, and the quantity in the bridge layer is always superior to that in the core layer. The distributions of places in the periphery layer, however, are much greater and wider than the other two layers. (2) The SINB connected compactly over time, bearing much resemblance to a small-world network. (3) Two patterns of connection, each with different connecting ratios between layers, appear on weekdays and weekends, respectively. Our research plays a vital role in understanding urban spatial heterogeneity, and helps to support decisions in urban planning and traffic management.

Download Full-text

Electric field effect on dynamic analysis of smart porosity-dependent nanocomposite sandwich plate resting on silica aerogel foundation considering carbon nanotubes agglomeration

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x19873417 ◽

2019 ◽

Vol 30 (18-19) ◽

pp. 2651-2669

Author(s):

Mohammad Hossein Zamani ◽

Mohammad Heidari-Rarani ◽

Alireza Ariaei

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Silica Aerogel ◽

Sandwich Plate ◽

Core Layer ◽

Smart Structure ◽

Geometrical Parameters ◽

Equivalent Material ◽

Electric Field Effect ◽

The Core

In this study, the influence of carbon nanotubes agglomeration is investigated on the electroelastic dynamic behavior of a sandwich plate. The smart sandwich plate consists of functionally graded porous layer as the core and piezoelectric layers as the face sheets, which is subjected to the harmonic electrical loading. In order to take into account the continuum model for the silica aerogel foundation of the smart structure, the modified Vlasov’s model is applied. The porosity distribution of the core layer varies non-uniformly throughout the thickness due to the non-uniform function. The equivalent material properties of nanocomposite core layer are determined using the Eshelby–Mori–Tanaka approach, in which the influence of carbon nanotube agglomeration is considered. For modeling the electroelastic fact sheets behavior, the piezoelasticity theory is adopted. On the basis of non-polynomial shear and normal deformation theory, the governing equations of motion are inferred applying the Hamilton’s principle and the obtained equations are solved by an iterative procedure. The verification is accomplished through the available results in the literature and the influences of carbon nanotube agglomeration, different geometrical parameters, porosity index, and applied voltage are assessed on the dynamic deflection of nanocomposite sandwich plate.

Download Full-text

Testing of Precast Lightweight Foamed Concrete Sandwich Panel with Single and Double Symmetrical Shear Truss Connectors under Eccentric Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.1107 ◽

2011 ◽

Vol 335-336 ◽

pp. 1107-1116 ◽

Cited By ~ 13

Author(s):

Noridah Mohamad ◽

Hilmi Mahdi Muhammad

Keyword(s):

Sandwich Panel ◽

Core Layer ◽

Surface Strain ◽

Structural Performance ◽

Eccentric Load ◽

Composite Action ◽

The Core ◽

Steel Rebar ◽

Foamed Concrete ◽

Single Shear

This paper reports the structural behavior of precast lightweight foamed concrete sandwich panel, PLFP, subjected to eccentric loading. An experiment was conducted to investigate the structural performance of PLFP under this load. Two PLFP panels, PE-1 and PE-2 were cast with 2000 mm in heights, 750 mm in width and 100 mm in thickness. The thickness of the wall is actually a combination of three layers. Skin layers were cast from lightweight foamed concrete while the core layer is made of polystyrene. The skin layers were connected to each other by 9 mm steel shear truss connector which were embedded through the layers. Panel PE-1 was strengthened with single diagonal shear truss connectors made of 6 mm steel rebar while panel PE-2 was strengthened with symmetrical diagonal shear truss connectors of similar steel diameter. Both panels were tested under eccentric load till failure. The results showed that panel with symmetrical double truss connectors, PE-2, is able to sustain higher load compared to panel with single shear truss connector. The load-deflection profiles indicate that both panels achieved certain degree of composite action especially during the later stage of loading where the wythes tend to move in the same direction until they reached failure. The load-strain curves for both panels highlight the inconsistent distribution of surface strain along the height of panels. The overall trend of the strain curves show that they are under compression.

Download Full-text