scholarly journals Karakteristik Mekanik Panel Honeycomb Sandwich Berbahan Komposit Fibreglass dengan Dimensi Cell-Pitch 40mm dan Cell-Height 30mm

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Marsono Marsono ◽  
Ali Ali ◽  
Nico Luwis
Keyword(s):  
Cell Wall ◽  
Flexural Strength ◽  
Wall Thickness ◽  
Energy Efficient ◽  
Sandwich Panel ◽  
Honeycomb Structure ◽  
Cell Wall Thickness ◽  
Bending Test ◽  
Increase Energy Efficiency ◽  
Honeycomb Sandwich

ABSTRAKRekayasa struktur honeycomb sandwich dalam pengembangan material banyak telah dimanfaatkan karena memiliki kekuatan struktur yang relatif tinggi dengan bobot material yang ringan. Material dengan rekayasa struktur honeycomb cocok digunakan pada mobil hemat energi, untuk meningkatkan efesiensi energi. Dalam penelitian ini dibuat panel honeycomb sandwich berbahan komposit serat kaca (fibreglass) dan matirks resin. Panel ini nantinya akan diterapkan pada rangka kendaraan hemat energi. Tiga panel honeycomb sandwich dibuat dengan variasi pada ketebalan dinding sel terutama ditujukan untuk mengetahui pengaruh ketebalan dinding sel terhadap kekuatan dan kekakuan panel honeycomb sandwich. Variasi ketebalan dinding sel didapatkan dari variasi penerapan jumlah lapisan fiberglass pada dinding sel honeycomb, yaitu 2 lapis, 4 lapis dan 6 lapis fibreglass. Hasil pengujian bending menunjukkan bahwa panel honeycomb sandwich dengan ketebalan dinding sel terbesar, yaitu dengan 6 lapisan fibreglass, memberikan kekuatan lentur terbesar yaitu 3,774 kg/mm2, dan kekakuan tertinggi, yaitu 21,48 kg/mm.Kata kunci: honeycomb sandwich, komposit fibreglass, kekuatan lentur, kekakuan.  ABSTRACTEngineering of honeycomb sandwich structure in the materials development has been highly utilized because of its high structural strength with lightweight material. Honeycomb structure material is suitable for use in energy-efficient cars, to increase energy efficiency. In this research, sandwich honeycomb panel were made from fibreglass composite with resin as matrices. This panel will be applied to the frame of energy-efficient vehicle. Three sandwich honeycomb panels were made with variations in cell wall thickness. These variations are primarily intended to determine the effect of cell wall thickness to the flexural strength and stiffness of the honeycomb sandwich panel. Variations in cell wall thickness were obtained from variations in the application of fibreglass layers on honeycomb cell walls, which are 2 layers, 4 layers and 6 layers of fibreglass. The bending test results show that the honeycomb sandwich panel with the largest cell wall thickness, which has 6 layers of fibreglass, provides the greatest flexural strength of 3.774 kg/mm2, and the highest stiffness of 21.48 kg/mm.Keywords: honeycomb sandwich,fibreglass composite , flexurall strength, stiffness.

J041042 Local Compression Fatigue of Peripherally Clamped Honeycomb Sandwich Panel : Influence of Cell Wall Thickness

2011 ◽  
Vol 2011 (0) ◽  
pp. _J041042-1-_J041042-5
Author(s):  
Nao AKIYAMA ◽  
Hisao HIRASIMA ◽  
Yoshinao KISHIMOTO ◽  
Yukiyosi KOBAYASHI ◽  
Toshihisa OHTSUKA
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Sandwich Panel ◽  
Cell Wall Thickness ◽  
Honeycomb Sandwich

Evaluation of elastic constants of A3003 honeycomb core with varying hexagonal cell geometries through finite element approach

2013 ◽  
Vol 228 (10) ◽  
pp. 1689-1700 ◽  
Author(s):  
S Rajkumar ◽  
D Ravindran ◽  
Ramesh S Sharma ◽  
VP Raghupathy
Keyword(s):  
Finite Element ◽  
Cell Wall ◽  
Elastic Constants ◽  
Wall Thickness ◽  
Sandwich Panel ◽  
Load Transfer ◽  
Cell Wall Thickness ◽  
Honeycomb Core ◽  
Finite Element Approach ◽  
Element Approach

Aluminum honeycomb core is one of the most sought after material for the sandwich panel for light weight applications. While the aluminum face sheet is isotropic, the honeycomb core assumes orthotropic characteristics due to its configuration and strenuous load transfer paths. It is now well established that stiffness, dynamic, and low velocity impact response of the honeycomb core sandwich panel are critically dependent on the elastic constants of the core. An attempt is made to determine the elastic constants of orthotropic core through finite element approach simulating the load transfer and fixity boundary conditions likely to be prevalent in the unit cell of the honeycomb core. The cell wall thickness and the cell shape dictated by plastic bending limitations have also been simulated to determine their influence on the elastic constants. Further, the cell wall thickness and the bend radius have been varied and their influence on orthotropic elastic constants has been determined. The results of the study have been compared with analytical solutions proposed by researchers. The finite element procedure evolved is a simple, efficient, and quick solution methodology to accurately predict elastic constants of honeycomb core depicting the exact cell size and shape.

scholarly journals Effect of Cell Wall Thickness on Local Compression Fatigue Property of Honeycomb Core Sandwich Panel

2012 ◽  
Vol 78 (787) ◽  
pp. 299-310 ◽  
Author(s):  
Yukiyoshi KOBAYASHI ◽  
Toshihisa OHTSUKA ◽  
Yoshinao KISHIMOTO ◽  
Syougo INUMA ◽  
Yuuki OHTSU
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Sandwich Panel ◽  
Fatigue Property ◽  
Cell Wall Thickness ◽  
Honeycomb Core

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

Characterization of microstructures of SAN foam core using micro-computed tomography

2021 ◽  
pp. 026248932110068
Author(s):  
Youming Chen ◽  
Raj Das ◽  
Hui Wang ◽  
Mark Battley
Keyword(s):  
Cell Wall ◽  
Cell Size ◽  
Wall Thickness ◽  
Strain Localization ◽  
Cell Wall Thickness ◽  
Micro Computed Tomography ◽  
Average Cell Size ◽  
Average Cell ◽  
3D Images ◽  
Compressive Tests

In this study, the microstructure of a SAN foam was imaged using a micro-CT scanner. Through image processing and analysis, variations in density, cell wall thickness and cell size in the foam were quantitatively explored. It is found that cells in the foam are not elongated in the thickness (or rise) direction of foam sheets, but rather equiaxed. Cell walls in the foam are significantly straight. Density, cell size and cell wall thickness all vary along the thickness direction of foam sheets. The low density in the vicinity of one face of foam sheets leads to low compressive stiffness and strength, resulting in the strain localization observed in our previous compressive tests. For M80, large open cells on the top face of foam sheets are likely to buckle in compressive tests, therefore being another potential contributor to the strain localization as well. The average cell wall thickness measured from 2D slice images is around 1.4 times that measured from 3D images, and the average cell size measured from 2D slice images is about 13.8% smaller than that measured from 3D images. The dispersions of cell wall thickness measured from 2D slice images are 1.16–1.20 times those measured from 3D images. The dispersions of cell size measured from 2D slice images are 1.12–1.36 times those measured from 3D images.

Summer temperature in northeastern Siberia since 1642 reconstructed from tracheid dimensions and cell numbers of Larix cajanderi

2003 ◽  
Vol 33 (10) ◽  
pp. 1905-1914 ◽  
Author(s):  
Irina P Panyushkina ◽  
Malcolm K Hughes ◽  
Eugene A Vaganov ◽  
Martin AR Munro
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Cell Number ◽  
Cell Wall Thickness ◽  
Cell Dimension ◽  
Cell Numbers ◽  
Age Related ◽  
Cambial Age ◽  
Northeastern Siberia ◽  
Larix Cajanderi

We reconstructed air temperature for two periods in the growth season from cell dimension and cell number variability in cross-dated tree rings of Larix cajanderi Mayr. from northeastern Siberia. Thirteen tree-ring chronologies based on cell size, cell wall thickness, and cell number were developed for AD 1642–1993. No clear evidence was found of an age-related trend in cell dimensions in the sampled materials, but cell numbers were correlated with cambial age. The chronologies contain strong temperature signals associated with the timing of xylem growth. We obtained reliable reconstructions of mean June temperature from the total cell number and July–September temperature from the cell wall thickness of latewood. June temperature and July–September temperature covaried for most of the period from AD 1642 to AD 1978. After that time, June temperature became cooler relative to July–September temperature. This difference caused disproportional changes in earlywood tracheids because of the late start of growth and cool conditions in June followed by warming during the rest of the season. The identification of this unusual recent change has shown that intraseasonal resolution may be achieved by cell dimension and cell number chronologies.

Variation in xylem anatomy of selected populations of lodgepole pine

2001 ◽  
Vol 31 (11) ◽  
pp. 2049-2057 ◽  
Author(s):  
Tongli Wang ◽  
Sally N Aitken
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Slow Growth ◽  
Lodgepole Pine ◽  
High Density ◽  
Cell Wall Thickness ◽  
Fast Growth ◽  
Low Density ◽  
Xylem Anatomy ◽  
Latewood Density

Variation in xylem anatomy among selected populations of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) was examined using digital image analysis based on an annual growth ring (age 10) per tree. Four subpopulations were selected using the following criteria for height growth and wood density: (i) fast growth and high density; (ii) slow growth and high density; (iii) fast growth and low density; and (iv) slow growth and low density. Significant differences were found among subpopulations for several anatomical parameters including tracheid density, lumen size, and cell wall thickness that may affect the economic value and utilization of wood. Principal component analysis indicate that the first four principal components (PCs) were associated with (i) ring area (PC1), (ii) earlywood density (PC2), (iii) latewood density (PC3), and (iv) lumen shape in earlywood (PC4), suggesting that these aspects of wood properties and growth are controlled by different sets of genes. Relative contributions of total number of tracheids, tracheid lumen size, and cell wall thickness to ring area and correlations between cell wall area proportion and X-ray density are discussed.

scholarly journals Host Barriers and Responses to Uncinula necator in Developing Grape Berries

2004 ◽  
Vol 94 (5) ◽  
pp. 438-445 ◽  
Author(s):  
Andrea Ficke ◽  
David M. Gadoury ◽  
Robert C. Seem ◽  
Dale Godfrey ◽  
Ian B. Dry
Keyword(s):  
Cell Wall ◽  
Powdery Mildew ◽  
Wall Thickness ◽  
Infection Process ◽  
Cell Wall Thickness ◽  
Antifungal Compound ◽  
Uncinula Necator ◽  
Grape Berries ◽  
Pathogenesis Related ◽  
Cuticle Thickness

Grape berries are highly susceptible to powdery mildew 1 week after bloom but acquire ontogenic resistance 2 to 3 weeks later. We recently demonstrated that germinating conidia of the grape powdery mildew pathogen (Uncinula necator) cease development before penetration of the cuticle on older resistant berries. The mechanism that halts U. necator at that particular stage was not known. Several previous studies investigated potential host barriers or cell responses to powdery mildew in berries and leaves, but none included observation of the direct effect of these factors on pathogen development. We found that cuticle thickness increased with berry age, but that ingress by the pathogen halted before formation of a visible penetration pore. Cell wall thickness remained unchanged over the first 4 weeks after bloom, the time during which berries progressed from highly susceptible to nearly immune. Autofluorescent polyphenolic compounds accumulated at a higher frequency beneath appressoria on highly susceptible berries than on highly resistant berries; and oxidation of the above phenolics, indicated by cell discoloration, developed at a significantly higher frequency on susceptible berries. Beneath the first-formed appressoria of all germinated conidia, papillae occurred at a significantly higher frequency on 2- to 5-day-old berries than on 30- to 31-day-old fruit. The relatively few papillae observed on older berries were, in most cases (82.8 to 97.3%), found beneath appressoria of conidia that had failed to produce secondary hyphae. This contrasted with the more abundantly produced papillae on younger berries, where only 35.4 to 41.0% were located beneath appressoria of conidia that had failed to produce secondary hyphae. A pathogenesis-related gene (VvPR-1) was much more highly induced in susceptible berries than in resistant berries after inoculation with U. necator. In contrast, a germin-like protein (VvGLP3) was expressed within 16 h of inoculation in resistant, but not in susceptible berries. Our results suggest that several putative barriers to infection, i.e., cuticle and cell wall thickness, antimicrobial phenolics, and two previously described pathogenesis-related proteins, are not principal causes in halting pathogen ingress on ontogenically resistant berries, but rather that infection is halted by one or more of the following: (i) a preformed physical or biochemical barrier near the cuticle surface, or (ii) the rapid synthesis of an antifungal compound in older berries during the first few hours of the infection process.

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