scholarly journals Influence of Structural Reinforcements on the Twist-to-bend Ratio of Plant Stems

2020 ◽  
Author(s):  
Steve Wolff-Vorbeck ◽  
Olga Speck ◽  
Thomas Speck ◽  
Patrick Dondl
Keyword(s):  
Cross Sections ◽  
Torsional Rigidity ◽  
Biological Evolution ◽  
Strong Increase ◽  
Fibre Reinforcement ◽  
Vascular Bundles ◽  
Element Analysis ◽  
Epidermal Tissue ◽  
Mechanical Quality

Abstract During biological evolution, plants have developed a wide variety of body plans and concepts that enable them to react or adapt to changing environmental conditions. Their morphological-anatomical and mechanical adaptations to conflicting conditions are especially interesting. A good example is the trade-off between flexural and torsional rigidity, as represented by the dimensionless twist-to-bend ratio. We have developed geometric models of a plant tissue reflecting the 2D situation of triangular cross-sections comprising of a parenchymatous matrix with vascular bundles surrounded by an epidermis and analysed them by using mathematical models (finite element analysis) to measure the effect of either reinforcements of the epidermal tissue or fibre reinforcements such as collenchyma and sclerenchyma on the twist-to-bend ratio. The change from an epidermis to a covering tissue of corky periderm increases both the flexural and the torsional rigidity and decreases the twist-to-bend ratio. Furthermore, additional fibre reinforcement strands in a parenchymatous ground tissue lead to a strong increase of the flexural and a weaker increase of the torsional rigidity and thus resulting in a marked increase of the twist-to-bend ratio. Within the developed model, a reinforcement by 49 sclerenchyma fibre strands or 24 collenchyma fibre strands is optimal in order to achieve high twist-to-bend ratios. Dependent on the mechanical quality of the fibres, the twist-to-bend ratio of collenchyma-reinforced axes is noticeably smaller, with collenchyma having an elastic modulus that is approximately 20 times smaller than that of sclerenchyma.

scholarly journals Influence of structural reinforcements on the twist-to-bend ratio of plant axes: a case study on Carex pendula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Steve Wolff-Vorbeck ◽  
Olga Speck ◽  
Thomas Speck ◽  
Patrick W. Dondl
Keyword(s):  
Mathematical Models ◽  
Cross Sections ◽  
Torsional Rigidity ◽  
Biological Evolution ◽  
Strong Increase ◽  
Herbaceous Plant ◽  
Fibre Reinforcement ◽  
Vascular Bundles ◽  
Flower Stalk

AbstractDuring biological evolution, plants have developed a wide variety of body plans and concepts that enable them to adapt to changing environmental conditions. The trade-off between flexural and torsional rigidity is an important example of sometimes conflicting mechanical requirements, the adaptation to which can be quantified by the dimensionless twist-to-bend ratio. Our study considers the triangular flower stalk of Carex pendula, which shows the highest twist-to-bend ratios ever measured for herbaceous plant axes. For an in-depth understanding of this peak value, we have developed geometric models reflecting the 2D setting of triangular cross-sections comprised of a parenchymatous matrix with vascular bundles surrounded by an epidermis. We analysed the mathematical models (using finite elements) to measure the effect of either reinforcements of the epidermal tissue or fibre reinforcements such as collenchyma and sclerenchyma on the twist-to-bend ratio. The change from an epidermis to a covering tissue of corky periderm increases both the flexural and the torsional rigidity and decreases the twist-to-bend ratio. Furthermore, additional individual fibre reinforcement strands located in the periphery of the cross-section and embedded in a parenchymatous ground tissue lead to a strong increase of the flexural and a weaker increase of the torsional rigidity and thus resulted in a marked increase of the twist-to-bend ratio. Within the developed model, a reinforcement by 49 sclerenchyma fibre strands or 24 collenchyma fibre strands is optimal in order to achieve high twist-to-bend ratios. Dependent on the mechanical quality of the fibres, the twist-to-bend ratio of collenchyma-reinforced axes is noticeably smaller, with collenchyma having an elastic modulus that is approximately 20 times smaller than that of sclerenchyma. Based on our mathematical models, we can thus draw conclusions regarding the influence of mechanical requirements on the development of plant axis geometry, in particular the placement of reinforcements.

scholarly journals Design and Analysis of Eco Car Chassis with Different Profiles

2021 ◽  
Vol 9 (VII) ◽  
pp. 474-480
Author(s):  
E. Deepak Naidu
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
High Speed ◽  
Torsional Rigidity ◽  
Side Impact ◽  
Analysis Model ◽  
Element Analysis ◽  
Formula Sae ◽  
Race Car ◽  
Impact Side

Formula Student Racing competitions are held at various Formula SAE circuits globally. Chassis serves as an important component in the race car design. Thus a solicitous analysis is expected out of the formula car. It is also noted that the weight of the car is inversely proportional to the performance of the car hence need for optimization. A high speed protection system plays a major role in the race car design such as front impact, rear impact, side impact and roll over analysis. Also, there exists a problem of the torsional rigidity as far the dynamics is considered. This paper aims at the design aspects and the analysis insights of the race car. The car is modelled according to the 95th percentile male that can fit inside the cockpit of the chassis. As the car travel at the high speed, the protection has been designed to the car in such a way that stresses are minimum and the performance is maximum. Finite element methods are used for the analysis and the design of experiments is created for the optimization of the chassis. To avoid any possibilities of failure of the structure and thus to provide enough supporting member to make the region stronger in term of deformation . Finite element analysis enables to predict the region that tends to fail due to loading, the distribution of stress and strain on the chassis, both component as well as the material costing. The main objective is to study the effect of the validations of the FEM result are given using the different profiles like RECTANGLE, CIRCULAR, AND I SHAPE convergence methods for car body and the equipment. Keywords:-Chassis design; cross sections; Static analysis; Model analysis

scholarly journals BANANA LEAVES QUALITY OF Musa balbisiana Colla. AND Musa paradisiaca L. BASED ON ANATOMICAL STRUCTURE

2015 ◽  
Vol 2 (1) ◽  
pp. 361 ◽  
Author(s):  
Maryani _ ◽  
Puput Pratiwi
Keyword(s):  
Cross Sections ◽  
Vascular Bundle ◽  
Nutrient Content ◽  
Anatomical Structure ◽  
Vascular Bundles ◽  
Musa Balbisiana ◽  
Musa Paradisiaca ◽  
Cell Layers ◽  
Banana Leaves

<p>Indonesia is the main centre of banana biodiversity. Banana is preferred because of its high nutrient content and economical value. Besides, banana leaves, particularly from “Klutuk” banana (Musa balbisiana Colla.) is also well-known used as traditional wrapper of cakes and foods. The objective of this research was to know and to compare the anatomical structure of Musa balbisiana Colla. and Musa paradisiaca L. leaves, and their anatomical characters as quality indication of banana leaves used as cakes and foods wrapper. Cross sections of banana leaves were prepared using free hand section and paraffin embedding methods. Leaf clearing method was used to prepare upper and lower epidermal tissue slides. Parameters used were the arrangement of cells/tissues, length and width of vascular bundles, mesophyll thickness, the thickness of schlerenchyma tissue, the number of laticiferous and tanin cells, and stomata indexs. The data were analyzed using Analysis of Variance (Anova) continued by Duncan test at level 5%. The results showed that the anatomical structure of M.balbisiana Colla. and M. paradisiaca L. leaves consisted of epidermis, hypodermis, mesophyll, and vascular bundles. The supporting tissues were composed of sclerenchyma located at upper and lower side of vascular bundle. The number of cell layers composing upper and lower hypodermis; stomata number, stomata index, the length and width of stomata; the thickness of vascular bundles; the thickness of layers composing adaxial and abaxial mesophyll; the thickness of schlerenchyma layers and width of schlerenchyma tissue at vascular bundle as well as laticiferous and tannin cell were found differently between M. balbisiana Colla. and M. paradisiaca L. The values of meshophyll thickness, length and width of vascular bundle, the thickness of schlerenchyma tissue, the number of laticiferous cells and the number of tanin cells were higher for M. paradisiaca L than in M. balbisiana Colla. The smaller the thickness of schlerenchyma layers and the width of schlerenchyma tissue at vascular bundle as well as the less number of laticiferous and tannin cells were assumed to be correlated with the good quality of M. balbisiana Colla leaves as foods and cakes wrapper. </p><p><strong>Keywords</strong>: anatomy, banana leaves, Musa balbisiana Colla., Musa paradisiaca L.</p>

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

scholarly journals Comparison of Screening Configurations for the Mitigation of Voltages and Currents Induced on Pipelines by HVAC Power Lines

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3855
Author(s):  
Arturo Popoli ◽  
Leonardo Sandrolini ◽  
Andrea Cristofolini
Keyword(s):  
Finite Element Analysis ◽  
Cross Sections ◽  
Detrimental Effect ◽  
Power Line ◽  
Skin Depth ◽  
Power Lines ◽  
Element Analysis ◽  
3D Finite Element ◽  
Different Shapes ◽  
High Magnetic Permeability

In this paper, a strategy for reducing the electromagnetic interferences induced by power lines on metallic pipelines is proposed and numerically investigated. The study considers a set of steel conductors interposed between the power line and the pipeline. Different shapes of conductor cross sections and different magnetic permeabilities are considered, to identify the solution exhibiting the greatest mitigation efficiency for the same amount of material. The investigation is carried out by means of a quasi-3D finite element analysis. Results show that the main mechanism responsible for the mitigation is constituted by the currents induced in the screening conductors by the power line. Hence, a high magnetic permeability can have a detrimental effect since it reduces the skin depth to values below the size of the screening conductor. In this case, a reduction of the screening current and in the mitigation efficiency is observed. Nevertheless, the study shows that the use of strip-shaped screening conductors allows the employment of cheaper magnetic materials without compromising the mitigation efficacy of the screening conductors.

scholarly journals Probing of the internal damage morphology in multilayered high-temperature superconducting wires

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
You-He Zhou ◽  
Cong Liu ◽  
Lei Shen ◽  
Xingyi Zhang
Keyword(s):  
Magnetic Flux ◽  
Layer Structure ◽  
Extreme Environment ◽  
Uniaxial Tensile ◽  
Internal Damage ◽  
Amorphous Phases ◽  
Superconducting Wires ◽  
Mechanical Quality ◽  
Loading System

AbstractThe second generation HTS wires have been used in many superconducting components of electrical engineering after they were fabricated. New challenge what we face to is how the damages occur in such wires with multi-layer structure under both mechanical and extreme environment, which also dominates their quality. In this work, a macroscale technique combined a real-time magneto-optical imaging with a cryogenic uniaxial-tensile loading system was established to investigate the damage behavior accompanied with magnetic flux evolution. Under a low speed of tensile strain, it was found that the local magnetic flux moves gradually to form intermittent multi-stack spindle penetrations, which corresponds to the cracks initiated from substrate and extend along both tape thickness and width directions, where the amorphous phases at the tip of cracks were also observed. The obtained results reveal the mechanism of damage formation and provide a potential orientation for improving mechanical quality of these wires.

Numerical Analysis of Masonry under Compression via Micro-Model

2011 ◽  
Vol 243-249 ◽  
pp. 1360-1365 ◽  
Author(s):  
Wei Rong Lü ◽  
Meng Wang ◽  
Xi Jun Liu
Keyword(s):  
Joint Strength ◽  
Ultimate Load ◽  
Poor Quality ◽  
Micro Model ◽  
Element Analysis ◽  
Mortar Joint ◽  
The Poor ◽  
The Finite Element Analysis ◽  
Brick And Mortar

The micro-model, which the brick and the mortar model are separated, is used to analyze masonry. Meanwhile, the mortar is divided into three layers along the thickness direction to obtain the internal mechanical behavior of mortar, and the vertical mortar joint strength is taken as 50% strength of the horizontal mortar joint for considering the poor quality of vertical mortar joint. The compressive ultimate load and failure mode of masonry taken from the finite element analysis result, especially the vertical cracks throughout all bricks and mortar and change of brick and mortar strain, are in agreement with the experimental results. It shows that the micro-model and method adopted in paper are able to effectively apply in nonlinear structural analysis for masonry.

Benefits of Using Diamond Dies for Cold Alternate Drawing of Magnesium Alloys

2016 ◽  
Vol 716 ◽  
pp. 13-21 ◽  
Author(s):  
Vladimir Stefanov Hristov ◽  
Kazunari Yoshida
Keyword(s):  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Wire Drawing ◽  
High Ductility ◽  
Element Analysis ◽  
The Wire ◽  
Shearing Strain ◽  
Drawing Method

In recent years, due to its low density and high strength/weight ratio, magnesium alloy wires has been considered for application in many fields, such as welding, electronics, medical field (for production of stents). But for those purposes, we need to acquire wires with high strength and ductility. For that we purpose we proposed alternate drawing method, which is supposed to highly decrease the shearing strain near the surface of the wire after drawing, by changing the direction of the wire drawing with each pass and thus acquiring high ductility wires.We have done research on the cold alternate drawing of magnesium alloy wires, by conducting wire drawing of several magnesium wires and testing their strength, hardness, structure, surface and also finite element analysis, we have proven the increase of ductility at the expense of some strength.In this research we are looking to further improve the quality of the drawn wires by examining the benefits of using diamond dies over tungsten carbine dies. Using the alternate drawing method reduces the strength of the drawn wires and thus lowering their drawing limit. By using diamond dies we are aiming to decrease the drawing stress and further increase the drawing limit of the alternate drawn wires and also improve the quality of the finishing surface of the wires. With this in mind we are aiming to produce a good quality wire with low diameter, high ductility, high strength and fine wire surface.

The Analysis of Reinforcing the Bottom Chord around the Tapped Holes Based on the Thermosetting Resin Composite Materials

2012 ◽  
Vol 531 ◽  
pp. 609-612
Author(s):  
Xue Dong Han ◽  
Li Wei ◽  
Gang Luo ◽  
Li Ping Chang
Keyword(s):  
Composite Material ◽  
Resin Composite ◽  
Steel Bridge ◽  
Stress Distributions ◽  
Element Analysis ◽  
Steel Truss Bridge ◽  
The Finite Element Analysis ◽  
Before And After ◽  
Truss Bridge

The intensity of the joint in the bottom chord would affect the quality of the whole bridge because that the force of the bottom-through bridge is transferred mainly through the bottom chord, and the members of the truss connect each other by using the thread. In this paper, the bottom chord around the tapped holes is reinforced by composite material , and the stress on the bottom chord is analyzed before and after the reinforcement using the finite element analysis method, and the stress distributions in the directions of X,Y and Z on every layer of the composite material under the bilateral reinforcing condition are extracted and compared. The results show that: Reinforcing the bottom chord around the tapped holes using the composite material can change the stress level of the bottom chord effectively, helping to improve the quality of the construction of the steel bridge and the effect of the bilateral reinforcing is better than the unilateral reinforcing and providing certain reference for the security of the steel truss bridge

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