Natural Fibers vs. Synthetic Fibers Reinforcement: Effect on Resistance of Mortars to Impact Loads

2022 ◽  
Author(s):  
Mahmoud Saad ◽  
Vincent Sabathier ◽  
Anaclet Turatsinze
Keyword(s):  
Natural Fiber ◽  
Impact Load ◽  
Natural Fibers ◽  
Polypropylene Fiber ◽  
Ultrasonic Waves ◽  
Impact Loads ◽  
Compression Tests ◽  
Experimental Protocol ◽  
Identity Card ◽  
The Impact

Given their specific properties, their natural and renewable sources and their low environmental impact in production, natural fibers offer an opportunity for the development of eco-friendly cement-based composites. The main objective of this experimental work is to evaluate the resistance to the impact load of mortars incorporating natural fibers or polypropylene fibers at 28 days. The assessment was carried out according to an experimental protocol developed in our laboratory. The method consists in dropping a metallic ball on a square shaped specimen of 30x30x2 cm3 to determine the energy supported by each sample. For each specimen, the number of blows required for the first crack initiation and for the total collapse of specimen are detected using a device allowing to measure the speed of ultrasonic waves. The device was fixed on the specimen itself. In order to fulfill the mechanical identity card of the composites, flexural and compression tests were also carried out at 28 days. In this experimental protocol, the pozzolanic binder was considered with different fiber percentages of polypropylene (0.25% and 0.5% by mass of binder) and of natural fibers (0.5% and 1% by mass of binder). All fibers have a length of 12 mm. Results show that natural fiber reinforcement could be considered as an ecological alternative to polypropylene fiber one to improve the resistance of mortars to impact loads.

scholarly journals Karakterisasi Mekanik Komposit Matriks Polipropilena High Impact Dengan Serat Alam Acak Dengan Metode Hand Lay Up Untuk Komponen Automotive

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Alfan Ekajati Latief ◽  
Nuha Desi Anggraeni ◽  
Dedy Hernady
Keyword(s):  
Tensile Strength ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Natural Fibers ◽  
Mesh Size ◽  
High Impact ◽  
Hemp Fiber ◽  
Polypropylene Matrix ◽  
The Impact ◽  
Pineapple Leaves

ABSTRAK Serat alam yang berfungsi sebagai penguat memiliki sifat yang lebih ringan, mudah dibentuk, tahan korosi, harga murah dan memiliki kekuatan yang sama dengan material logam. Serat bahan alami yang memiliki kekuatan tarik, tekan dan impak yang baik diantaranya serat rami dan daun nanas. Untuk matriks Polipropilena high impact (PPHI) yang banyak digunakan dalam industri otomotif.. Pada penelitian ini dipelajari pengaruh fraksi volume serat alami terhadap sifat mekanik komposit PPHI berpenguat serat alami. Komposit PPHI dibuat dengan menggunakan metode Hand Lay Up pada temperatur 2500C dengan fraksi volume serat alami sebesar 10%, dimana serat dibuat digunting halus hingga memiliki ukuran mesh 120/170, 170/200 dan dibawah 200 mesh, Kekuatan tarik komposit diukur dengan mengacu pada standar ASTM 3039, kekuatan tekan diukur mengacu pada ASTM D 695. Harga Impak dari komposit diukur dengan mengacu pada ASTM D 6110-04. Pada penelitian ini dapat disimpulkan, fraksi volume 10 % serat alami yang baik ketika dicampur dengan matriks polipropilena high impact adalah serat nanas dengan meshing 170/200 dapat meningkatkan kekuatan tarik PPHI sebesar 40 % dan meningkatkan harga impak PPHI sebesar 50,8 % jika dilihat penelitan sebelumnya yakni menggunakan serat rami dibawah mesh 1200 dengan matriks PPHI. Kata Kunci: Rami, Daun Nanas, Polipropilena High Impact, Hand Lay Up. ABSTRACT Natural fibers that function as reinforcement have lighter properties, are easily formed, are corrosion resistant, are cheap and have the same strength as metal materials. Natural fiber which has good tensile, compressive and impact strength including Ramie and pineapple leaves. For high impact polypropylene matrix (PPHI) which is widely used in the automotive industry. In this study the effect of volume fraction of natural fibers on the mechanical properties of PPHI composites with natural fiber reinforced properties was studied. PPHI composites are made using the Hand Lay Up method at a temperature of 2500C with a volume fraction of natural fibers of 10%, where fibers are made finely shaved to have a mesh size of 120/170, 170/200 and below 200 mesh, the tensile strength of the composite is measured by reference to the standard ASTM 3039, compressive strength measured refers to ASTM D 695. The impact price of the composite is measured with reference to ASTM D 6110-04. In this study it can be concluded, a good volume fraction of 10% natural fiber when mixed with high impact polypropylene matrix is pineapple fiber with meshing 170/200 can increase the tensile strength of PPHI by 40% and increase the impact price of PPHI by 50.8% if seen by research previously that used hemp fiber under mesh 1200 with PPHI matrix. Keywords: Ramie Pineapple, High Impact Polypropylene, Hand Lay Up.

scholarly journals Effect of Natural Fiber (NF) Mix on Mechanical Strength of NF Plastic Composites (NFPC)

2019 ◽  
Vol 9 (1) ◽  
pp. 5663-5667
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Natural Fiber ◽  
Fiber Type ◽  
Natural Fibers ◽  
Natural Fibre ◽  
Additional Advantage ◽  
Plastic Composites ◽  
Twin Screw ◽  
The Impact

Natural fibers from plants are gaining importance and may substitute wood in the production of wood plastic composites (WPC). To ensure continuity of fiber supply and sustainability of WPC industries, fibers of various types could be mixed together to obtain Mix WPC. However, research need to be carried out to identify the contribution of different fiber type collectively to the mechanical properties of Mix natural fiber polymer composite (NFPC). In this study, preliminary work on the use of natural fibre (NF) such as kenaf, sugar palm and pineapple leaf fibers in the preparation of Mix NFPC were carried out. Four different fiber mix samples with different fiber ratio and size were formulated using polypropylene (PP) as the polymer matrix. Montmorrilonite (MMT) filler was added at constant amount for enhancement of composite mechanical properties. Samples were mixed and prepared using a twin screw extruder and mini injection moulding resepectively. Individual fibers and NFPC prepared were characterized using thermogravimetric analyzer (TGA). Tensile, flexural and impact strength of the composites were determined. Generally, it was found that addition of fiber mix at 50% fiber loading enhance the tensile and flexural strength of the various NFPC with minimal exceptions. The impact strength of the composites were comparable to that of blank PP implying that addition of fiber gives additional advantage besides being eco-friendly. It was also found that higher kenaf loading and different size of fiber mix contribute positively to the various strengths measured. In addition to that, composition of individual fibers also contribute to the mechanical properties of the NFPCs

A Case for Avoiding Hydraulic Shock Suppressors (Snubbers) in the Vibratory Environments

2018 ◽  
Author(s):  
Kshitij P. Gawande ◽  
Phillip Wiseman ◽  
Alex Mayes
Keyword(s):  
Dynamic Load ◽  
Impact Load ◽  
Pressure Vessels ◽  
Mechanical Equipment ◽  
Internal Dynamic ◽  
Impact Loads ◽  
Hydraulic Shock ◽  
Dynamic Events ◽  
Piping Systems ◽  
The Impact

Whenever undesirable dynamic events occur within power plant, refinery, or process piping systems, specialty supports and restraints have the task of protecting the mechanical equipment and connecting piping from damaging loads and displacements. The array of components that may be affected include, but are not limited to, piping systems, pumps, valve assemblies, pressure vessels, steam generators, boilers, and heat exchangers. In particular, the dynamic events can be classified into two distinct types that originate from either internal events or external events. The internal dynamic load generating events include plant system start-up and shut-down, pressure surges or impacts from rapid valve closures such as steam and water hammer, boiler detonations, pipe rupture, and operating vibratory displacements that may be either low frequency or high frequency vibrations. The external dynamic load generating events include wind loads, earthquake, airplane impact to supporting structures and buildings, and explosions. Most of the aforementioned dynamic load generating events can be defined quite simply as impact loads, i.e., forces and moments that are applied over very short periods of time, for example, less than one second. While earthquake loads may be applied over a total time period of an hour or so, the peak loads and resulting displacements occur on a more sinusoidal basis of peak-to-peak amplitudes. One of the most common specialty restraint components utilized in the piping industry to absorb and transfer the dynamic load resulting from impact events is the hydraulic shock suppressor, otherwise known as the snubber. The snubber is a formidable solution to protecting plant piping systems and equipment from impact loading while not restricting the thermal displacements during routine operations. In the dynamic events that may be characterized by an impact type loading, snubbers provide an instantaneous, practically rigid, axial connection between the piping or other component to be secured and the surrounding structure whether it be concrete or steel (for example). In this way, the kinetic energy can be transmitted and harmlessly dissipated. In the vibratory environment, however, neither the impact load scenario nor the rapid translations are imposed upon snubbers, thereby presenting the competing intended application of the snubber to protect against impact loads versus, in many cases, the improper selection of the snubber to dampen vibratory (other than seismic) loads. The details of the hydraulic shock suppressor design are reviewed and discussed to exemplify why a case can and should be made against the use of snubbers in piping systems within an operating vibratory environment.

scholarly journals Failure Characteristics of Joint Bolts in Shield Tunnels Subjected to Impact Loads from a Derailed Train

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Qixiang Yan ◽  
Zhixin Deng ◽  
Yanyang Zhang ◽  
Wenbo Yang
Keyword(s):  
Impact Load ◽  
Numerical Study ◽  
Design Method ◽  
Shield Tunnel ◽  
Failure Behavior ◽  
Impact Loads ◽  
Fe Model ◽  
Fe Modelling ◽  
Bolt Failure ◽  
The Impact

Impact loads generated by derailed trains can be extremely high, especially in the case of heavy trains running at high speeds, which usually cause significant safety issues to the rail infrastructures. In shield tunnels, such impact loads may not only cause the damage and deformation of concrete segments, but also lead to the failure of segmental joint bolts. This paper presents a numerical study on the failure behavior of segmental joint bolts in the shield tunnel under impact loading resulting from train derailments. A three-dimensional (3D) numerical model of a shield tunnel based on the finite element (FE) modelling strategy was established, in which the structural behavior of the segmental joint surfaces and the mechanical behavior of the segmental joint bolts were determined. The numerical results show that the occurrence of bolt failure starts at the joints near the impacted segment and develops along the travel direction of train. An extensive parametric study was subsequently performed and the influences of the bolt failure on the dynamic response of the segment were investigated. In particular, the proposed FE model and the analytical results will be used for optimizing the design method of the shield tunnel in preventing the failure of the joint bolts due to the impact load from a derailed HST.

Rigid-plastic analysis of floating ice sheets under impact loads

1981 ◽  
Vol 8 (4) ◽  
pp. 409-415
Author(s):  
John B. Kennedy ◽  
K. J. Iyengar
Keyword(s):  
Impact Load ◽  
Design Method ◽  
Yield Criterion ◽  
Ice Sheets ◽  
Contact Radius ◽  
Impact Loads ◽  
Rigid Plastic ◽  
Deformation Response ◽  
Safe Thickness ◽  
The Impact

The deformation response of floating ice sheets under high intensity, short duration loads is examined. Using a rigid-plastic theory, together with a Tresca yield criterion, expressions are derived for the total time of response and the final deformed configuration of floating ice sheets. The influence of the magnitude of the impact load and the load-contact radius on the various design quantities such as deflection profile and stress distribution is discussed. Based on the results derived, a design method is presented to find the safe thickness of a floating ice sheet to sustain a given impact load. The method is illustrated with a numerical example.

scholarly journals A Study on Mechanical Behaviour of Surface Modified Rice Husk/Polypropylene Composite Using Sodium Hydroxide

2016 ◽  
Vol 8 ◽  
pp. 72-82
Author(s):  
Kannan Rassiah ◽  
Aidy Ali
Keyword(s):  
Sodium Hydroxide ◽  
Rice Husk ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Young Modulus ◽  
Hardness Test ◽  
Main Challenge ◽  
The Matrix ◽  
Surface Modified ◽  
The Impact

There are many studies has been done on the natural fibers of cellulose contents as a reinforcing material. Yet, the main challenge in the research of natural fiber is the poor compatibility. In this study, the surface modification techniques were performed on granular size rice husk (RH) such as untreated, boiled and sodium hydroxide (NaOH) treated reinforced polypropylene (PP) was consolidated to improve the mechanical properties. An internal mixer machine is set for four different composites compositions and the samples produced by hot press machine. The specimens were analyzed by different techniques such as hardness test, impact test, tensile test and scanning electron microscopy (SEM). This study shown that, the presence of NaOH indicates higher young modulus and hardness test value compared to boiled treated and untreated RH. While for the impact strength and tensile strength value shows untreated, boiled treated and NaOH treated PP/RH composite decreased when fiber loading increased. The morphological analysis was conducted to determine the effects of natural fiber bonding between the matrix materials after boiling and NaOH treatments for mechanical testing broken specimens.

scholarly journals Numerical Simulation of Modified Rubberized Concrete Block Under Impact Loads

2021 ◽  
Vol 1200 (1) ◽  
pp. 012022
Author(s):  
T Y Pei ◽  
S N Mokhatar ◽  
N A N A Mutalib ◽  
S J S Hakim
Keyword(s):  
Energy Absorption ◽  
Impact Load ◽  
Concrete Strength ◽  
Constitutive Models ◽  
Numerical Procedure ◽  
Concrete Block ◽  
Crumb Rubber ◽  
Impact Loads ◽  
Rubberized Concrete ◽  
The Impact

Abstract Rubberized concrete was innovated by many researchers to enhance energy absorption under impact load and by reusing scrap tires. Thus, this research was aims to develop the numerical procedure using the Finite Element Method (FEM) to simulate modified rubberized concrete under impact loads and predict its energy absorption under different impact loads. Three existing constitutive models: Concrete Damage Plasticity (CDP), Drucker-Prager (DP), and Modified Drucker-Prager Cap (MDPC) available in ABAQUS software were used to replicate the rubberized concrete with 10% of Rice Hush Ash (RHA) as cement substitution and different percentages (0%, 5%, 10%, 15%, and 20%) of crumb rubber as sand replacement. All three models produced successful FEM results with reasonable modelling assumption, and the CDP model was more effective in simulating rubberized concrete under impact to predict energy absorption than DP and MDPC models. Further, it was concluded that crumb rubber could enhance the energy absorption of concrete. Generally, the energy absorption of the concrete increased as the crumb rubber increase. However, the strength decreased as the crumb rubber increased, but 10% of RHA in concrete mix can maintain the concrete strength. Overall, this study reveals that FEM incorporated with the CDP model is able to predict the impact response of modified crumb rubber as an application of concrete road barrier.

scholarly journals PENGARUH PERLAKUAN ALKALISASI DAN VARIASI FRAKSI VOLUME KOMPOSIT POLYESTER SERAT BEMBAN (Donax Canniformis) TERHADAP KEKUATAN IMPAK

2016 ◽  
Vol 1 (2) ◽  
pp. 89-98 ◽  
Author(s):  
Akhmad Wahyudi ◽  
Akhmad Syarief
Keyword(s):  
Natural Resources ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Research Result ◽  
Natural Fibers ◽  
Composite Fiber ◽  
Absorption Energy ◽  
Material Forming ◽  
The Many ◽  
The Impact

The Indonesian state is rich in natural resources, the various benefits of natural resources are useful for human survival. Various kinds of plants in Indonesia are useful as technical material.One of the engineering materials is Composite. Composite is a material formed from a combination of two or more matrials that have stronger mechanical properties than the material forming. The composite consists of two parts: a matrix as a binder or a composite protector and a filler as a composite filler. Natural fiber is an alternative filler, and bemban fiber (Donax Canniformis) is one of the many natural fibers grown in the Hulu Sungai Selatan area of South Kalimantan. From the research result, the influence of volume fraction on composite fiber bemban has the most optimum strength that is on variation 60% fiber bemban 40% Polyester with no alkalization that has absorption energy 13.23 joule and the impact price of 0.067 joule / mm².

scholarly journals Effects of axial impact load on the dynamics of an oilwell drillstring

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983687
Author(s):  
Liping Tang ◽  
Xiaohua Zhu ◽  
Hongzhi Lin
Keyword(s):  
Sensitivity Analysis ◽  
High Frequency ◽  
Impact Load ◽  
Drill String ◽  
Impact Loads ◽  
Harmonic Force ◽  
Cross Sectional ◽  
Axial Impact ◽  
Energy Conservation Method ◽  
The Impact

This article studies the dynamics of oilwell drillstring under large and small axial impact loads. For the case of large impact load, the drillstring is regarded as a continuous bar under the impact load of a falling mass, and the energy conservation method is implemented. A sensitivity analysis is conducted to investigate the effect of cross-sectional area of the drill string on the impact stress. Results show that the design of drillstring with different cross-sectional areas is not a suitable method. In order to understand the effect of high-frequency small axial impact (applied from percussion tools or downhole generators) on the drillstring vibration, a mechanical model in which the drillstring is regarded as a 2-degree-of-freedom system under a harmonic force is developed. Sensitivity analysis on the effects of impact generator placement and impact frequency on drillstring dynamics are conducted. Results show that the impact generator should be installed near the drill bit and that high frequency is recommended to be used.

Experimental Study on Impact Resistant Performance of Steel Beams

2011 ◽  
Vol 94-96 ◽  
pp. 239-243
Author(s):  
Run Lin Yang ◽  
Yuan Li
Keyword(s):  
Impact Load ◽  
Experimental Testing ◽  
Composite Layer ◽  
Tube Steel ◽  
Strain History ◽  
Steel Beam ◽  
Impact Loads ◽  
Flexible Plate ◽  
Building Structures ◽  
The Impact

Impact damage of building structures occurs frequently nowadays, and failure of key components of the structures may lead to the collapse of the whole buildings which could cause serious consequences. Thus, it is necessary to study on the impact resistant performance of the members. The different protective measures against impact loads were examined through the experimental testing in this paper. A tube steel beam with the rectangle cross-section was selected as the tested object. During the experimental testing, the different weight of the drop hammers and the different shapes of the contact surfaces were designed for sake of comparison. The strain history at the middle span of the steel beam under the impact load was measured by a Fiber Bragg Grating sensor. By comparing the strain values, the experimental results show that the composite layer which consists of the rigid and the flexible plate is superior to the single layer which only consists of the rigid plate, and have a better effect for suppression of the dynamic response against the impact loads.

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