Compressive Strength Parallel to the Grain in Relation to Moisture Content in Calamus simplicifolius Cane

2020 ◽  
Vol 70 (3) ◽  
pp. 309-316
Author(s):  
Limei Yang ◽  
Xing'e Liu ◽  
Zehui Jiang ◽  
Genlin Tian ◽  
Shumin Yang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Three Dimensional ◽  
Fiber Surface ◽  
Dynamic Vapor Sorption ◽  
Linear Elastic ◽  
Fracture Behaviors ◽  
Calamus Simplicifolius ◽  
Average Compressive Strength ◽  
Loading Axis ◽  
Elastic Stage

Abstract This research aimed to investigate the compressive fracture behavior and the compressive strength parallel to the grain in relation to moisture contents (MC) below and above the fiber saturation point (FSP) in Calamus simplicifolius cane. FSP of the rattan was investigated using a dynamic vapor sorption (DVS) apparatus, and the fracture behaviors of compression parallel to grain were analyzed by three-dimensional X-ray microcomputed tomography. The study indicated that the value of FSP derived from the DVS method was 25 percent. The average compressive strength parallel to the grain was found to be 39 MPa at 3 percent MC, 30 MPa at 10 percent MC, 17 MPa at 12 percent MC, 12 MPa at 27 percent MC, and 10 MPa at 45 percent MC. The strains of the yield and densification stage were prolonged with increasing MC, whereas the stress in the linear elastic stage decreased with increasing MC. The cracks of the rattan core and the deflection angle at higher MC were larger than that of low MC. Below the FSP, the compressive failure of the rattan showed a shear band oriented around 45° to the loading axis, and the surface was rough. Above the FSP, the rattan samples showed brooming failure. The interface among fiber bundles was delaminated and the fiber surface in the failure area was smooth. The fracture toughness of the rattan was higher than that of wood, which suggests that the rattan might be more suitable for modeling and curved materials.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

scholarly journals Chitosan/Gelatin/PVA Scaffolds for Beta Pancreatic Cell Culture

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2372
Author(s):  
Yesenia Sánchez-Cardona ◽  
Claudia E. Echeverri-Cuartas ◽  
Marta E. Londoño López ◽  
Natalia Moreno-Castellanos
Keyword(s):  
Compressive Strength ◽  
Cell Viability ◽  
Pore Size ◽  
Three Dimensional ◽  
Ternary Blend ◽  
Ternary Blends ◽  
Binary Blend ◽  
Pancreatic Cell ◽  
Degradation Rates ◽  
Swelling Rate

Chitosan scaffolds based on blending polymers are a common strategy used in tissue engineering. The objective of this study was evaluation the properties of scaffolds based on a ternary blend of chitosan (Chi), gelatin (Ge), and polyvinyl alcohol (PVA) (Chi/Ge/PVA), which were prepared by cycles of freeze-thawing and freeze-drying. It then was used for three-dimensional BRIN-BD11 beta-cells culturing. Weight ratios of Chi/Ge/PVA (1:1:1, 2:2:1, 2:3:1, and 3:2:1) were proposed and porosity, pore size, degradation, swelling rate, compressive strength, and cell viability analyzed. All ternary blend scaffolds structures are highly porous (with a porosity higher than 80%) and interconnected. The pore size distribution varied from 0.6 to 265 μm. Ternary blends scaffolds had controllable degradation rates compared to binary blend scaffolds, and an improved swelling capacity of the samples with increasing chitosan concentration was found. An increase in Young’s modulus and compressive strength was observed with increasing gelatin concentration. The highest compressive strength reached 101.6 Pa. The MTT assay showed that the ternary blends scaffolds P3 and P4 supported cell viability better than the binary blend scaffold. Therefore, these results illustrated that ternary blends scaffolds P3 and P4 could provide a better environment for BRIN-BD11 cell proliferation.

Preparation of Porous HA Bioceramics by Gelcasting and Pressureless Sintering

2011 ◽  
Vol 335-336 ◽  
pp. 1454-1458
Author(s):  
Jing Xian Zhang ◽  
Bi Qin Chen ◽  
Dong Liang Jiang ◽  
Qing Ling Lin ◽  
Zhong Ming Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Pressureless Sintering ◽  
High Compressive Strength ◽  
Microstructure And Properties ◽  
Pmma Beads ◽  
Average Compressive Strength

In the present work, porous HA scaffolds with well controlled pore size, porosity and high compressive strength were prepared by aqueous gelcasting. PMMA beads with different size were used as the pore forming agent. The compositions, microstructure and properties of porous HA bioceramics were analyzed by XRD, SEM, Hg porosimetry etc. The mechanical properties were also tested. For scaffolds with the porosity as 70%, the average compressive strength was 11.9±1.7 MPa. Results showed that glecasting process can be used for the preparation of porous HA biomaterials with well controlled pore size and improved mechanical properties.

Assessment of Residual Ultimate Strength of VLCC According to Damage Extents and Average Compressive Strength of Stiffened Panel

2014 ◽  
Author(s):  
Ji-Myung Nam ◽  
Joonmo Choung ◽  
Se-Yung Park ◽  
Sung-Won Yoon
Keyword(s):  
Compressive Strength ◽  
Ultimate Strength ◽  
Probabilistic Approach ◽  
Stiffened Panel ◽  
Moment Capacity ◽  
Hull Girder ◽  
Damage Area ◽  
Damage Indices ◽  
Smith Method ◽  
Average Compressive Strength

This paper presents the prediction of residual ultimate strength of a very large crude oil carrier considering damage extents due to collision and grounding accidents. In order to determine extents of damage, two types of probabilistic approaches are employed: deterministic approach based on regulations based on ABS [1], DNV [2], and MARPOL [3] and probabilistic approach based on IMO probability density functions (PDFs) (IMO guidelines [4]). Hull girder ultimate strength is calculated using Smith method which is dependent on how much average compressive strength of stiffened panel is accurate. For this reason, this paper uses two different methods to predict average compressive strength of stiffened panel composing hull girder section: CSR formulas and nonlinear FEA. Calculated average compressive strength curves using CSR formulas (IACS [5, 6]) and nonlinear FEA are imported by an in-house software UMADS. Residual ultimate moment capacities are presented for various heeling angles from 0° (sagging) to 180° (hogging) by 15° increments considering possible flooding scenarios. Three regulations and IMO guidelines yield minimum of reduction ratios of hull girder moment capacity (minimum of damage indices) approximately at heeling angles 90° (angle of horizontal moment) and 180° (angle of hogging moment), respectively, because damage area is located farthest from neutral axis.

PEMANFAATAN LIMBAH KOTORAN SAPI SEBAGAI PENGGANTI SEBAGIAN SEMEN DALAM PEMBUATAN BATAKO

2020 ◽  
Vol 15 (2) ◽  
pp. 53-57
Author(s):  
Kiki Kurniawan ◽  
Prihantono Prihantono ◽  
Rosmawita Saleh
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Mean Value ◽  
Cow Dung ◽  
A Value ◽  
Average Water ◽  
Hollow Brick ◽  
Average Compressive Strength

The results showed the use of cow dung waste can increase the compressive strength of hollow brick from any composition of waste. Hollow brick with cow dung substitution of 0% has an average compressive strength value 44.75 Kg/Cm2 has an average water absorption of 14.31%, hollow brick with cow dung substitution of 5% has a value of compressive strength average 47.47 Kg/Cm2 has an average water absorption of 15.67%, Batako perforation with cow dung substitution of 7.5% has an average compressive strength value of 51.83 Kg/Cm2 has the absorption water averaging 13.71%, batako perforated with substitution of cow dung waste of 10% has an average compressive strength value 53.81 Kg/Cm2 has an average water absorption of 10.04%, hollow brick with substitution cow dung waste of 12.5% has an average compressive strength value of 50.66 Kg/Cm2 has an average water absorption of 23.6%, hollow brick with cow dung substitution of 15% average 48.84 Kg/Cm2 has an average water absorption of 19.72%. The optimum compressive strength value was obtained from percentage substitution of cow dung waste at 10% with mean value of compressive strength 53,81 Kg/Cm2 with average water absorption 10,04%.

Experimental Assessment of Strength Parameters of River Sand for Sandcrete Block Production

2021 ◽  
Vol 53 ◽  
pp. 67-75
Author(s):  
Babatunde Ogunbayo ◽  
Clinton Aigbavboa ◽  
Opeoluwa Akinradewo
Keyword(s):  
Compressive Strength ◽  
Quality Standard ◽  
Sieve Analysis ◽  
Building Structures ◽  
Strength Parameters ◽  
River Sand ◽  
Sieve Analyses ◽  
Aggregate Material ◽  
Average Compressive Strength ◽  
Minimum Quality

Sandcrete block is a vital building material used in the construction of building structures. The sandcrete blocks are produced by different manufacturers using river sand obtained from different locations as aggregate material without recourse to the minimum quality standard for the blocks produced. The study assessed the strength parameters of river sand used as an aggregate material in block production to determine its quality and suitability in relation to the strength of block produced. Three (3) block manufacturing sites in Nigeria were visited and 27 (twenty-seven) blocks of size 450 mm x 225 mm x 225 mm were selected randomly from the sites. The properties of the river sand was analyzed through sieve analyses, bulk density, silt content and water absorption while the compressive strength of the blocks was also tested. The result of sieve analysis of the river sand used in block production for this study all satisfied the particle size requirements of BS EN 933-1:1997 for general construction work including block production. The result of the study also shows that blocks produced with the river sand after 28days have an average compressive strength of 1.23 N/mm2 (SW), 1.54 N/mm2 (SE) and 1.95N/mm2 (NE). The study, therefore, concluded and recommended that regulatory and professional bodies in partnership with relevant associations should organize seminars for producers of sandcrete blocks on the best practices involved in producing quality sandcrete blocks.

Performance Based Evaluation of Bridge Substructure in North Mississippi Using Nonlinear FEM and Field Vibration Measurement

2000 ◽  
Author(s):  
Chris L. Mullen ◽  
Prabin R. Tuladhar
Keyword(s):  
Finite Element ◽  
Transfer Functions ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Vibration Measurement ◽  
Elastic Behavior ◽  
Evaluation Procedure ◽  
Vibration Measurements ◽  
Linear Elastic ◽  
Performance Based Evaluation

Abstract Discussion of a Performance - Based Engineering evaluation procedure for an existing interstate highway bridge in north Mississippi. The bridge is in a highly trafficked location near the Memphis Metropolitan area and is reflective of modern design practices in Mississippi. Results are presented of nonlinear damage response and displacement ductility performance of the reinforced concrete bents and their foundations predicted using static finite element (FE) computations. The model considers the composite action of the concrete and the reinforcing steel materials under axial force, shear, torsion and flexure. The performance-based evaluation includes three-dimensional computational simulations of the nonlinear bridge system, including substructures and superstructure. The response spectrum dynamic analysis method will also be carried out on the linear elastic three-dimensional model to predict the linear elastic behavior. Field vibration measurements, including ambient and hammer-impact, were performed to calibrate the models. The computed transfer functions are currently being evaluated to correlate vibration measurements and the Finite element models.

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