Composite Leaf Research Articles

Nutritional Status Assessment of Pistachio Orchards in Qazvin Plain, Iran

ABSTRACT Plant analysis is used to optimize the fertilizer applications and diagnosis of the plant nutrition disorders. In the present study, the standard norms for pistachio orchards have been calculated and compared using two methods of Compositional Nutrient Diagnosis (CND) and Deviation from Optimum Percentage (DOP) in Qazvin Plain (Iran). The composite leaf samples were taken from 200 pistachio orchards during three years (2017–2019) and concentrations of Manganese (Mn), Zinc (Zn), Iron (Fe), Magnesium (Mg), Calcium (Ca), Potassium (K), Phosphorus (P), Nitrogen (N), Boron (B), and Copper (Cu) were measured, along with recording the orchards’ yield. The results of CND method showed that the most frequency percentage of the nutrients deficiency was respectively belonged to Mn, Mg, and P in the orchards. Same results were obtained in DOP method. The priority of the nutrient’s deficiency in DOP method was as follows: Mn > Mg > P > K> Ca. In general, it is concluded that Mn, Mg, and P are the most limiting nutrients, are which due to being calcareous, high K content and low organic matter content of the soil, these deficiencies are justified. Therefore, it is recommended to use organic matters, P, Mg, and Mn to improve the yield of pistachio orchards.

Novel pineapple leaf fibre composites coating with antimicrobial compound as a potential food packaging

AbstractBiodegradable packaging coated with antimicrobial compounds has emerged as a new type of food packaging with potential to enhance food safety, extend shelf life and minimize plastic pollution. We have developed a polylactic acid (PLA) composite pineapple leaf fibre (PALF) biopolymer to fulfil the high demand of biodegradable materials for a potential use in food packaging. Our formulation with 10% pineapple fibre PLA/PALF composites exhibited enhanced melting temperatures and heat resistance, with a 44% reduction in the tensile strength and 2.7‐fold reduction on the strain at the break when compared with neat PLA. To impart antimicrobial activity, the PLA/PALF was coated with crude supernatants isolated from Pediococcus pentosaceus PP04 containing 1.3% w/v of nisin. This material coated with the crude extract was shown to inhibit the growth of Bacillus cereus ATCC 11778, Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311, and Escherichia coli ATCC 8739 in culture conditions, as well as minimizing the number of the tested pathogens on coated material surfaces.

Fabrication of polymer hybrid composites for automobile leaf spring application

Presently, the automobile industry is focusing to replace conventional leaf spring with hybrid composite leaf spring owing to its lesser weight and high strength. Hence, the aim of current investigation is to fabricate a polymer (epoxy) based hybrid composites for light commercial vehicles to investigate their flexural strength, and wear behavior. For this two hybrid composites using carbon, kevlar and Jute fibres having different thicknesses (3 mm and 4 mm) were fabricated using hand lay-up technique. Further, the fabricated hybrid composite samples have been tested under three-point bending test as per ASTM D7264 standard and compared it with conventional leaf spring material (Steel). Thereafter, the wear behavior of the both samples was measured. From the results, it has been found that the hybrid composites offered 44% and 173% high flexural strength respectively for 3 mm and 4 mm thick hybrid composite in comparison to conventional material, also the weight reduction of 66% and 57% respectively.

Kiwifruit Metabolomics-An Investigation of within Orchard Metabolite Variability of Two Cultivars of Actinidia chinensis.

Plant metabolomics within field-based food production systems is challenging owing to environmental variability and the complex architecture and metabolic growth cycles of plants. Kiwifruit cultivars of Actinidia chinensis are vigorous perennial vines grown as clones in highly structured orchard environments, intensively managed to maximize fruit yield and quality. To understand the metabolic responses of vines to orchard management practices, we needed to better understand the various sources of metabolic variability encountered in the orchard. Triplicate composite leaf, internode and fruit (mature and immature) samples were collected from each of six Actinidia chinensis var. deliciosa ‘Hayward’ and A. chinensis var. chinensis ‘Zesy002’ kiwifruit vines at three times during the growing season and measured by LC-MS. In general, there was more variation in metabolite concentrations within vines than between vines, with ‘Hayward’ showing a greater percentage of within-vine variability than ‘Zesy002’ (c. 90 vs. 70% respectively). In specific tissues, the sampler, infection by Pseudomonas syringae var. actinidiae and the rootstock also influenced metabolite variability. A similar pattern of metabolic variability was observed from quantitative analysis of specific carbohydrates and phytohormones. High within-vine metabolic variability indicates that it is more important to obtain sufficient replicate samples than to sample from multiple vines. These data provide an objective basis for optimizing metabolite sampling strategies within kiwifruit orchards.

Investigation and prediction of hybrid composite leaf spring using deep neural network based rat swarm optimization

Two different alternatives over conventional leaf spring are developed in this work, such as composite and hybrid composite-based leaf springs. In composite type, carbon-epoxy based multi-leaf springs are used and the combination of metal and carbon fiber material is used to develop hybrid composite leaf springs. The outputs namely deflection, maximum stress, and fatigue tests are determined using the finite element analysis approach. Besides, the optimal outcomes are set as the target for hybrid deep neural network-rat swarm optimization based prediction. The findings shows that the hybrid composite leaf spring provides better and enhanced results than the composite leaf spring.

Optimization and Weight Reduction of Hybrid Composite Leaf Spring

Weight decrease is one of the significant boundaries in plan of car segments. Such decrease helps to improve the eco-friendliness and execution of the vehicle, the variables which have specific importance in present situation of quickened non-renewable energy source consumption just as a dangerous atmospheric deviation concerns. The current work is aimed to design and analyse hybrid composite leaf spring, in commercial vehicles. For this reason, measurements of leaf spring used in broadly acclaimed business vehicle Tata 407 have been utilized. The goal is to compare the stress, deformation and weight decrease feasible through utilization of crossover/hybrid composite leaf spring when contrasted with regular leaf spring. The composite material selected for this purpose is glass fibre reinforced polymer (E-glass/epoxy). It has been observed that material combination of 2 Eglass + 3EN45 results in weight reduction of 18.14 kg in one leaf spring, which is practically 50% of the conventional leaf spring. lEglass +4sup9 have 50% higher cost than the conventional spring but have lower stress value compared to conventional leaf spring & has achieved weight reduction of 14.77 kg in one leaf spring.

Design, Manufacturing and Analysis of Composite Leaf Spring

Now-a-days it is necessary to conserve natural resources, economize energy and weight reduction. Weight reduction of vehicle has become the main issue in Automobile Industries. It can be achieved by introduction of better material, design optimization and better manufacturing process. The Automobile Industry has interest for replacement of Steel Leaf Spring with Composite Leaf Spring. Composite Material has High Strength and Stiffness to Weight Ratio. The Objective is to compare the Stresses, Deformation, Elastic Strain and Weight of Composite Leaf Spring with that of Steel Leaf Spring. The Material Selected is Glass Fibre Reinforced Polymer is used against Conventional Steel. The Leaf Spring was modelled in CATIA and analysis done in ANSYS Software.

Modal Strain Energy based Crack Inspection in Mono Composite Leaf Spring

Modal Strain Energy based Crack Inspection in Mono Composite Leaf Spring

Experimental analysis of orthotropic strength properties of non-crimp fabric based composites for automotive leaf spring applications

We investigated the feasibility of a transversely isotropic approach to assess the strength properties during the design of a composite leaf spring. A modified Arcan test setup was developed to test the strength properties of the used non-crimp fabric based material in all orthotropic directions. Through comparisons with standardized coupon test methods for fiber-reinforced materials, a notch stress factor for tensile and shear load was derived. Our results indicate that fabric influences the material’s strength, and the assumption of transverse isotropy behavior is invalid. The measured transverse tensile strength was lower by a factor of 2.2 in the out-of-plane direction than in the in-plane direction, possibly leading to a lower resistance of leaf springs against delamination. Process induced differences did not significantly affect the measured strength in the tested directions. These findings will be useful in developing leaf springs with increased fatigue resistance.

Enhancement of Mechanical Properties of Hybrid Composite Materials

A hybrid composite materialsare one of the types to provide good suspension in wheeled vehicles application.By reducing weight of suspension systems, lowers total fuel exhaustion and costs.One of the most common approaches is to replace steel components with composite materials.To improve safety, comfort, and durability, composite have been introduced. Composite materials are corrosion resistant, have a good strength-to-weight ratio, and can store a lot of elastic strain. The aim of this study is to look into the structural properties of a hybrid compositematerials made of 95 percent Epoxy, 5% rubber, 5% glass fiber, and 5% hybrid composite of rubber and glass fiber. Since it has advantages over other approaches, hand layup was used in the fabrication. The mechanical experiments were used to determine the efficacy of the proposed composite leaf spring. We performed tensile, impact, hardness tests. When reinforcing fibers were used, the experimental results showed an improvement in hardness, impact, tensile strength. after the reinforcing fibers have been added, the best mechanical test results were obtained when hybrid reinforcement was used.

Structure Design of GFRP Composite Leaf Spring: An Experimental and Finite Element Analysis.

Due to the high load-bearing capacity and light weight, composite leaf spring with variable width and variable thickness has been increasingly used in the automobile industry to replace the conventional steel leaf spring with a heavy weight. The optimum structural design of composite leaf spring is particularly favorable for the weight reduction. In this study, an effective algorithm is developed for structural optimization of composite leaf spring. The mechanical performance of composite leaf spring with designed dimensions is characterized using a combined experimental and computational approach. Specifically, the composite leaf spring with variable width and variable thickness was prepared using the filament winding process, and the three-dimensional finite element (FE) model of the designed composite leaf spring is developed. The experimental sample and FE model of composite leaf spring are tested under the three-point bending method. From experimental and simulation results, it is shown that the bending stiffness of the designed leaf spring meets the design requirement in the automotive industry, while the results of stress calculation along all directions meet the requirements of material strength requirement. The developed algorithm contributes to the design method for optimizing the stiffness and strength performance of the composite leaf spring.

Dynamic behaviors of composite leaf springs with viscoelastic cores

A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Due to their high strength to weight ratio, high stiffness, and high impact energy absorption, fiber-reinforced composite leaf springs gain considerable interest recently as a potential alternative to conventional leaf springs with relatively high weight. In the present study, a novel composite leaf spring consists of two composite face layers, and a soft and flexible viscoelastic core is proposed. Employing viscoelastic materials in structures reduces undesirable vibrations leading to fatigue and damage of structures. A numerical method is used to design and analyze composite leaf springs with a viscoelastic core using the Abaqus software package. Results are compared with those from well-known analytical methods, finite element methods, and experiments. Results show that the proposed novel composite leaf spring can withstand the stresses caused by static and impact forces, reduce post-impact vibrations, and prevent undesirable system vibrations. The viscoelastic layer increases the strain energy capacity of proposed composite leaf springs compared to conventional composite leaf springs and enhances the composite leaf spring performance against bump impact.

A review of composite leaf springs for automotive vehicles

In the quest to conserve natural resources and economic energy. Weight reduction has been the focus of auto-manufactures and the aerospace industry in the present day. Weight reduction can be archived primarily by introducing better design optimization, better material, and improved manufacturing processes. This approach by introducing composite materials into automobile industries, which has high strength to weight ratio and excellent corrosive resistance, can fulfil the requirement. This review paper investigates the use of composite materials in the design of leaf springs for automotive vehicles. The paper underscores the suitability of composite materials for leaf spring in automobiles and develops a new leaf spring design that optimizes weight reduction and strength. The review provides details regarding previous efforts conducted on the design of leaf springs while outlining the knowledge gap areas. This review commences with an introduction to leaf springs and a brief history of their development. Followed by the properties that make an excellent leaf spring, this helps narrow down the information required for further developments providing avenues for possible future research.

Multi objective parametric optimization and composite material performance study for master leaf spring

Design optimization of product with the objective of reducing weight is one of current focuses in a product design. In the vehicle industry, in particular, weight reduction has significant impact on vehicle efficiency improvement and the fuel economy. These improvements can have direct impact on operating costs of the vehicle. The methods used to weight reduction are by optimizing the product́s parameters and by replacing conventional materials with highly sustainable materials strengths. In this paper, design model of existing master leaf spring has been created and optimized using SolidWorks parametric optimization with a goal of reducing the weight of leaf spring, improving the life span of structure by reducing stress and increasing the natural frequency of the leaf spring. The constraint used was limiting stress and natural frequency with the leaf spring’s thickness and width as optimization variables. Optimum values of these parameters of the leaf spring were obtained. Again, using parametrically optimized leaf spring model static and modal analysis was studied under two different composite materials, Epoxy Carbon UD Prepreg and Epoxy E-Glass UD, aiming to get minimum weight and improved life span compared to steel material (55SiMn90). The result shows that the leaf spring of composite materials performed better in terms of the stress level, stiffness and the natural frequency. At the same time, the weight of the composite leaf spring has significantly reduced. In summary, the study concluded that composite leaf spring is better efficient compared with conventional leaf spring from steel.

Stiffness Prediction and Analysis of Composite Leaf Springs

Composite leaf springs represent a key application of composite materials in the field of automotive lightweight materials. Stiffness, as a critical parameter of composite leaf springs, is closely related to the handling stability and ride comfort of automobiles. Therefore, this paper proposes an explicit theoretical model, which can consider the anisotropy of composite materials and detailed structure of the leaf spring, to predict the stiffness based on the law of energy conservation. The obtained results are verified against the results of the finite element method and bench test of basalt/epoxy samples. Moreover, the influence of the relevant design parameters on the stiffness is analyzed to provide guidance for the stiffness matching of composite leaf springs. The thickness of the composite leaf spring considerably influences its stiffness. As a key parameter representing the bearing capacity, the strength is closely related to the reliability of leaf springs. Based on the Tasi-Wu strength failure criterion, the influence of the relevant design parameters on the strength ratio of a composite leaf spring is analyzed under the constraint of stiffness. An increase in the width of the composite leaf spring enhances its bearing capacity when the stiffness is required to be within a certain range.

Design and Static Analysis of Mono Composite Leaf Spring Made of Various Types of Composite Materials Using Finite Element Method

In this study design and static analysis of mono composite leaf spring are performed in comparison to the existing structural steel leaf spring. The basic idea behind this work is to replace the existing structural steel leaf spring with composite materials. In this work, three different kinds of composite materials are taken such as laminated Carbon/Epoxy, Boron/Aluminum, and Carbon/Epoxy (Non-Laminated) with the same thickness, width, and load-carrying capacity. The main investigation of the study is to reduce the weight of existing structural steel leaf spring while upholding its strength. This study seeks to address, improving load-carrying capacity, and designing less stressed and lightweight mono composite leaf spring. In this study, 60% fiber volume fraction and 40% matrix volume fraction are taken. In present work total deflection and equivalent von-misses stresses induced in the different kinds of mono composite leaf spring are compared with total deflection and equivalent von-misses stresses of conventional structural steel leaf spring. For analysis purposes, Ansys workbench 19.2 is used and for modeling of composite leaf spring, NX 10 (Unigraphics) is used. Finally, from the static analysis results, it has been observed that the newly designed composite leaf spring made of Carbon/Epoxy (Non-Laminated) has better performance than the existing conventional structural steel leaf spring.

STRESS DISTRIBUTION ON COMPOSITE HONEYCOMB SANDWICH STRUCTURE FOR A LEAF SPRING

Lightweight composite leaf spring of honeycomb sandwich structures are laminated composite structures that are composed of thin stiff face sheets bonded to a thicker lightweight core in between aluminum honeycomb in that honeycomb structure filled with foam.

Short-term dynamics of leaf litter-derived soil organic carbon under different coffee and cocoa cropping systems

Litter plays a crucial role in the formation of soil organic carbon (SOC), and potentially affects different pools in the context of soil carbon cycle. To improve knowledge and understanding with respect to the dynamics of carbon in coffee and cocoa cropping systems, there is a need to develop a mechanistic model to explain the formation of carbon especially in different background of soil, climate and agronomic management. Short-term observation was performed in different cropping systems, i.e. coffee (Coff) and cocoa (CoL) with lamtoro(Leucaena sp.) shade trees, and cocoa with oil palm (Elaeis guineensis) shade trees (CoP), and teak (Tectona grandis) conservation area, to investigate the quantitative amount of leaf litter-derived carbon. Additionally, to improve the understanding with respect to the formation of soil organic carbon, a simple model is developed by employing organic carbon storage coefficient (hi) as parameter to validate the observation data from Coff and CoL plots. Leaf litter is collected daily with concomitant microclimate records, i.e. air temperature, relative humidity, light intensity, and soil temperature. Composite soil and leaf samples are collected for organic carbon, soil moisture content, and leaf relative water content (RWC), for laboratory identification. Analysis of data suggests the presence of cropping system effect, i.e. shading condition and agronomical practices such as pruning, to microclimate variations except for soil temperature. Furthermore, cropping systems do not significantly influence soil moisture content, amount of organic carbon, and RWC. With higher model efficiency (EF), the simulated model fits better for CoL, EF 0.95, than Coff, EF 0.58. Model simulation, with both hi values are 0.017 and 0.014 in Coff and CoL, reveals a possibly cropping system specific curve pattern. A faster SOC formation in Coff plot has suggested a crucial role the amount of leaf litter to support with continuous carbon supply. The simulation implies the presence of soil related-maximum point limiting carbon storage capacity

Experimental investigation of textile structure reinforced composite leaf spring for their cyclic flexural and creep behaviour

This work dealt with the investigation of cyclic flexural strength and time dependent creep behavior of E-glass/epoxy-based different textile structure reinforced (chopped fibers, unidirectional (UD), bidirectional plain woven (2D), and 3D woven solid structures (orthogonal and Interlock) composite leaf spring. All textile structures were developed using a rigid rapier mutibeam weaving machine. Four different 3D woven orthogonal structures with varying binder percentage (3, 7, 10, and 13%) were developed to optimize weaving construction parameters for leaf spring application. The 3D orthogonal reinforced composite leaf spring exhibited improved cyclic flexural and creep performance and 3S1B stuffer-binder combination was found with the highest initial flexural strength, lowest drop in cyclic flexural strength and improved creep resistance. UD based composite leaf spring exhibited comparable properties to 3S1B based composite leaf spring. Composite leaf springs were further analyzed for their surface damage (tensile side) due to cyclic flexural loading. Structural variation (binder percentage) of 3D structure reinforced leaf spring has a significant influence on their failure (surface damage) morphology. 3D woven composite leaf spring with minimum binder tow percentage was found to be a potential material for automotive leaf spring from cyclic flexural strength, creep resistance, stiffness retention and failure morphology point of view.

FEA of Composite Leaf Spring for Light Commercial Vehicle: Technical Note

The intent of automotive sector for 21st century is to save fuel and reduce emissions. Due to this, the automotive designers are revisiting automotive systems and its parts for reducing the mass of the vehicles. For a suspension system, leaf spring is one of the key targets for weight reduction because it adds to unsprung mass which affects the ride quality of the vehicle. In this present study, a novel material such as a glass fiber reinforced plastic (GFRP) was selected. The polyester resin was used for conducting the numerical analysis via finite element analysis technique using ANSYS R15.0 software. Stresses, deformation and strain energy results for both steel and composite leaf spring material were obtained. Result shows that, the composite spring has a maximum strain energy than the steel leaf spring. The design constraints were stresses, deformations and strain energy. Compared to the steel spring, the composite spring (S-glass fiber) resulted in higher deformation, strain energy and stress.