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An assessment of HDPE fillers and Fiber Wrapping on the strength of Reinforced Concrete HDPE填料和纤维包裹对钢筋混凝土强度的评价
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.16
B. Gudadappanavar, Dilip Kulkarni, Shivakumar Gouda
Fiber-reinforced polymer (FRP) is the most promising technique in the present era to bring sustainability, reliability, and pseudo ductility to concrete structures due to its superior properties. Thermoplastic and thermoset polymers are the most thrown-out synthetic waste that contributes to environmental pollution for a long time. Knowing this issue an attempt was made to use High-Density Polyethylene Fiber (HDPE) fillers of size 40x2 mm has been used in concrete. This investigation aims to estimate the integrity effect of HDPE fillers incorporation and wrapping of concrete with Basalt fiber mats (BFM) and Geo-textile fiber mats (GFM) on split tensile strength, shear strength, and impact resistance as per standards. Results indicate that the addition of an optimum quantity of HDPE has a significant effect on improving the tensile, shear, and impact strengths. Adding HDPE fillers in the range of 0.5 - 1.5% in concrete samples wrapped with Basalt and Geo-textile fiber mats showed an increased tensile strength of up to 14.06% and 7.40% respectively with that conventional concrete. Further, wrapping of concrete using Basalt fiber and geotextile fiber mats showed a 4.16% and 20% increase in shear strength for 0.5% HDPE-incorporated concrete samples. Higher impact resistance was also observed for HDPE-added and fiber-wrapped concrete samples.
纤维增强聚合物(FRP)由于其优越的性能,是当前最有希望为混凝土结构带来可持续性、可靠性和伪延性的技术。热塑性和热固性聚合物是长期以来造成环境污染最严重的合成废物。考虑到这一问题,在混凝土中尝试使用尺寸为40x2 mm的高密度聚乙烯纤维(HDPE)填料。本研究旨在评估HDPE填料掺入和包裹玄武岩纤维垫(BFM)和土工纤维垫(GFM)混凝土对劈裂抗拉强度、剪切强度和抗冲击性的完整性影响。结果表明,添加最佳量的HDPE对提高材料的拉伸、剪切和冲击强度有显著作用。在玄武岩和土工纤维包裹的混凝土样品中加入0.5 ~ 1.5%的HDPE填料,抗拉强度分别比常规混凝土提高14.06%和7.40%。此外,使用玄武岩纤维和土工布纤维垫包覆混凝土时,掺入0.5% hdpe的混凝土样品的抗剪强度分别提高了4.16%和20%。添加hdpe和纤维包裹的混凝土样品具有更高的抗冲击性。
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引用次数: 0
Free vibration analysis of the structural integrity on the porous functionally graded plates using a novel Quasi-3D hyperbolic high order shear deformation theory 基于准三维双曲高阶剪切变形理论的多孔功能梯度板结构完整性自由振动分析
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.18
M. hadj Meliani, Mohammed Amine Kenanda, F. Hammadi, Zakaria Belabed
In this study, a novel quasi-three dimensional hyperbolic high-order shear deformation theory (quasi-3D HHSDT) is developed for free vibration analysis of porous functionally graded plates (FGPs). There are six unknowns in the current displacement field, and no shear correction factor is required. The mechanical properties are varied continuously through the thickness of porous FG plates using a modified power law function while considering the effect of porosities on the plate’s structural integrity. Two distinct porosity distribution models are considered, including even and uneven porosity distributions. The Navier technique is employed to obtain the closed-form solutions of motion's equations. An exhaustive parametric study is presented to show the influence of the different parameters on the fundamental frequencies.
本文提出了一种适用于多孔功能梯度板自由振动分析的准三维双曲高阶剪切变形理论(准3d HHSDT)。当前位移场有6个未知数,不需要剪切修正系数。在考虑孔隙率对结构完整性影响的情况下,利用修正幂律函数计算了多孔FG板的力学性能随厚度的变化规律。考虑了孔隙度均匀分布和不均匀分布两种不同的孔隙度分布模型。采用纳维叶技术求解运动方程的闭型解。给出了一个详尽的参数研究,以显示不同参数对基频的影响。
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引用次数: 2
Mechanical and Fracture Characterization of Epoxy/PLA/Graphene/SiO2 Composites 环氧树脂/PLA/石墨烯/SiO2复合材料的力学和断裂性能
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.15
K. Dileep, A. Srinath, N. Banapurmath, M. A. Umarfarooq, A. M. Sajjan
This work investigated the effects of graphene and SiO2 addition on the mechanical and fracture properties of epoxy (80%) - Polylactic acid (PLA) (20 %) composites. Epoxy-PLA composites were loaded with graphene and SiO2 (0.1-0.5 wt. % with equal weightage of each filler), and were manufactured by bath sonication followed by manual casting.  The tensile, flexural strength and fracture toughness of nanocomposites increased with an increase in filler concentration till it reached 0.3 wt. %. The addition of filler content higher than 0.3 wt. % drastically reduced the mechanical and fracture properties. The fractured surfaces from the tensile tests were examined using Scanning electron microscopy imaging to understand the effects of filler addition. The numerical analysis was also performed to simulate the impact of filler concentration on the tensile strength of nanocomposites using representative volume element (RVE) in ANSYS workbench.
研究了石墨烯和SiO2的添加对环氧(80%)-聚乳酸(20%)复合材料力学性能和断裂性能的影响。环氧PLA复合材料负载有石墨烯和SiO2(0.1-0.5wt.%,每种填料的重量相等),并通过浴超声处理和手动铸造制造。纳米复合材料的拉伸、弯曲强度和断裂韧性随着填料浓度的增加而增加,直到达到0.3wt.%。填料含量高于0.3重量%的添加大大降低了机械性能和断裂性能。使用扫描电子显微镜成像检查拉伸试验的断裂表面,以了解添加填料的影响。在ANSYS工作台上使用代表性体积单元(RVE)对填料浓度对纳米复合材料拉伸强度的影响进行了数值分析。
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引用次数: 0
Optimization of S-N curve fitting based on neighborhood rough set reduction with improved firefly algorithm 基于改进firefly算法的邻域粗糙集约简的S-N曲线拟合优化
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.17
Yangjinyu Li, Li Zou, Zhengjie Zhu
S-N curve fatigue samples of titanium alloy welded joints have such a comparatively significant scatter, that results in the issue that the fatigue life prediction accuracy is not optimal. In this work, the titanium alloy welded joints' fatigue data is used as analysis data, and the neighborhood rough set reduction with improved firefly algorithm efficient method of fitting stress-life curves is set forth. The welded joint's fatigue decision system is built with fatigue data. The continuous iteration of the firefly algorithm is used as the search strategy, the neighborhood rough set is adopted to decrease attributes, and the major deciding elements of welded joints' fatigue life is identified. The fatigue characteristic domains are divided based on the neighborhood rough set reduction with improved firefly algorithm's key factor set, and the S-N curves can then be fitted to each domain individually. According to the goodness-of-fit analysis, the proposed approach can improve fatigue life accuracy and reduce sample scattering from fatigue.
钛合金焊接接头S-N曲线疲劳试样具有比较显著的离散性,导致疲劳寿命预测精度不是最优。本文以钛合金焊接接头的疲劳数据为分析数据,提出了采用改进萤火虫算法进行邻域粗糙集约简的应力寿命曲线拟合的有效方法。利用疲劳数据建立了焊接接头的疲劳决策系统。采用萤火虫算法的连续迭代作为搜索策略,采用邻域粗糙集进行属性约简,识别出影响焊接接头疲劳寿命的主要因素。利用改进萤火虫算法的关键因子集,基于邻域粗糙集约简对疲劳特征域进行划分,然后将S-N曲线分别拟合到每个域上。拟合优度分析表明,该方法可以提高疲劳寿命精度,减少疲劳散射。
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引用次数: 0
The influence of notch connection location on the short-term behaviour of timber-concrete composite beams, modelling of TCC beams and research for optimal locations, a numerical study 缺口连接位置对木-混凝土组合梁短期性能的影响,TCC梁的建模和最佳位置的研究,数值研究
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.12
Hedmessaoud Zinelaabidine, Boudaoud Zeineddine, Ferhoune Noureddine
Timber-concrete composite beams, known as TCC beams, have been widely used in rehabilitation or in new buildings where several types of connections are commonly inserted to ensure partial composite action between the timber joist and the concrete slab. The notched connections represent an effective system due to their strength and ductility and it is simple to cut from timber joists. As a result, a small number is needed for the composite beam to achieve high performance in terms of bending stiffness and load-carrying capacity. This paper aims to develop a FE model for TCC beams with notched connections. It considers realistic interactions between different components. The developed FE model can satisfactorily predict the full range load-mid-span deflection curves and the failure mechanisms. The predictions agree very well with the experimental results reported in the literature, including the stiffness and the load-carrying capacity. After the validation, a numeric study was established, it aimed to research the optimal location of a notch connection between different proposed locations, to figure out which place must be installed to ensure high performance of the TCC beams. As a result of this study, the notch installed at location P3000 was found to be the optimal location to assure the highest bending stiffness. While the maximum carrying capacity was achieved at location P3750.
木-混凝土组合梁,即TCC梁,已广泛用于修复或新建建筑物,通常在这些建筑物中插入几种类型的连接,以确保木托梁和混凝土板之间的部分组合作用。由于其强度和延展性,缺口连接代表了一个有效的系统,并且很容易从木材托梁上切割。因此,复合梁在抗弯刚度和承载能力方面需要很小的数值来实现高性能。本文旨在建立具有缺口连接的TCC梁的有限元模型。它考虑不同组件之间的实际交互。所建立的有限元模型能较好地预测全跨度荷载-跨中挠度曲线和破坏机理。预测结果与文献报道的试验结果非常吻合,包括刚度和承载能力。验证后,建立了数值研究,旨在研究不同建议位置之间缺口连接的最佳位置,找出必须安装的位置以确保TCC梁的高性能。研究结果表明,安装在P3000位置的缺口是保证最高抗弯刚度的最佳位置。而最大承载能力是在位置P3750。
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引用次数: 0
Fracture analysis of defect Chlorinated Poly Vinyl Chloride pipes based on burst pressure and prediction their fraction of life 基于破裂压力的缺陷氯化聚氯乙烯管断裂分析及寿命预测
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.14
Fatima Gugouch, Achraf Wahid, Y. Bassir, M. Elghorba
Most Chlorinated Poly Vinyl Chloride (CPVC) resins contain 63-69 % chlorine, in particular those used for the extrusion of plumbing tubes, due to this chlorination of basic PVC, CPVC offers a mixture of corrosion resistance and low installation costs for its main applications requiring service in non-ambient conditions. CPVC replaces copper owing to its economic gain and by virtue of its pressure resistance characteristics. In this article, we have been interested in fracture analysis and damage modeling of CPVC tubes by subject CPVC samples to burst pressure tests. We performed a set of burst tests on virgin and artificially damaged CPVC pipe at different notch lengths, then submitted the specimens to burst pressure tests, in addition to recording the pressure and time during these tests for use in conducting the study. The results of the burst tests were exploited to estimate the damage and reliability of the material, these two parameters allow us to follow the degradation of the pipes used; subsequently, we determined a new relationship between these two parameters through the fraction life. This makes it possible to predict the moment of damage acceleration and to intervene at the right time for engaging predictive maintenance.
大多数氯化聚氯乙烯(CPVC)树脂含有63- 69%的氯,特别是那些用于管道挤压的树脂,由于基本PVC的氯化,CPVC提供了耐腐蚀性和低安装成本的混合物,其主要应用需要在非环境条件下使用。CPVC以其经济效益和耐压特性取代了铜。在本文中,我们对CPVC管的断裂分析和损伤建模感兴趣,通过CPVC样品进行破裂压力试验。在不同缺口长度的CPVC管道上分别进行了原始和人工损坏CPVC管道的爆破试验,并将试样提交进行了爆破压力试验,并记录了试验过程中的压力和时间,以供研究使用。利用爆炸试验的结果来估计材料的损坏和可靠性,这两个参数使我们能够跟踪所用管道的退化;随后,我们通过分数寿命确定了这两个参数之间的新关系。这使得预测损坏加速的时刻成为可能,并在适当的时间进行干预,进行预测性维护。
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引用次数: 2
Evaluating the Safety and the Effect of Blast Loading on the Shotcrete together with lattice girder Support of Tunnels 爆破荷载对隧道喷射混凝土与格梁支护的安全性及影响评价
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.08
Farnoosh Basaligheh, Hamidreza Karimi Tabar, M. Nikkhah
Damage to tunnels caused by explosions may damage the support structure and the stability. This damage is due to either blasting the working face for drilling progress or an explosion inside the tunnel. The present study investigates the dynamic parameters resulting from the blasting pattern on the temporary support structure of the tunnel considered as a lattice girder and shotcrete equivalent cross-section. For this purpose, LS-DYNA finite element software was used to assess the dynamic response of the structure to the vibration of the blasting-induced explosion. The peak particle velocity (PPV) was considered to evaluate the safety of the tunnel under dynamic loads. According to the results of this study, by exceeding the velocity of 0.9 m/s in the elements, some levels of destruction will occur. Regarding the elements of the temporary support structure of the tunnel, it is found that the damage occurs near the face and 2 m from the tunnel.
爆炸对隧道的破坏可能会破坏支护结构和隧道的稳定性。这种破坏是由于钻孔过程中工作面爆破或隧道内爆炸造成的。本文研究了考虑格梁和喷射混凝土等效截面的隧道临时支护结构的爆破方式所产生的动力参数。为此,采用LS-DYNA有限元软件评估结构对爆破振动的动力响应。采用峰值颗粒速度(PPV)来评价动荷载作用下隧道的安全性。根据本研究的结果,当元素的速度超过0.9 m/s时,会发生一定程度的破坏。对隧道临时支护结构构件进行分析,发现破坏主要发生在工作面附近和距离隧道2 m处。
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引用次数: 1
Experimental and numerical investigations of the flexural behaviour ‎of Green - Ultra High Performance Fiber Reinforced Concrete ‎beams under repeated loads 重复荷载作用下绿色超高性能纤维混凝土梁弯曲性能的试验与数值研究
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2023-03-21 DOI: 10.3221/igf-esis.64.10
Ayman Abdo Ayman Abdo, Ramadan Asker Ramadan Asker, Dina Atif sobhy, Sayed Ahmed Sayed Ahmed
There are various benefits to ultra-high-performance fiber-reinforced concrete ‎‎(UHPFRC). However, using a lot of cement in this type of concrete has a severe disadvantage since it causes pollution and several environmental concerns. Therefore, another type of concrete that achieves the same superior properties as UHPFRC while using less cement in the mixture should be considered. This research examined replacing cement with fly ash to produce environmentally friendly concrete called Green-UHPFRC. The impact of utilizing G-UHPFRC on the flexural behaviour of thirteen beams was investigated experimentally and numerically under repeated loads. The major parameters of the study were fly ash replacement ratios of 15%, 30%, and 45% and adding steel fiber to mixes with ratios of 1, 2, 3, and 4%. The tested beams were compared to the control beam in their backbone and hysteresis curves, failure load, crack propagation and failure modes, energy dissipation, stiffness degradation, and ductility index. From the results obtained, environmentally friendly concrete (G-UHPFRC) can be produced by replacing cement with fly ash up to 45% and adding 2% steel fiber without affecting the bending performance of beams made of G-UHPFRC compared to those made of UHPFRC.
超高性能纤维增强混凝土(UHPFRC)有很多优点。然而,在这种类型的混凝土中使用大量水泥有一个严重的缺点,因为它会造成污染和一些环境问题。因此,应考虑使用另一种混凝土,既能达到与UHPFRC相同的优越性能,又能减少混合料中水泥的用量。这项研究检验了用粉煤灰代替水泥来生产被称为Green-UHPFRC的环保混凝土。在重复荷载作用下,研究了G-UHPFRC对13根梁抗弯性能的影响。研究的主要参数为粉煤灰替代率分别为15%、30%、45%,钢纤维的掺量分别为1、2、3、4%。试验梁与对照梁在主梁和滞回曲线、破坏荷载、裂纹扩展和破坏模式、能量耗散、刚度退化和延性指标等方面进行了比较。结果表明,在不影响G-UHPFRC梁与UHPFRC梁的抗弯性能的前提下,用掺量为45%的粉煤灰代替水泥,加入2%的钢纤维,可以制备出环保型混凝土(G-UHPFRC)。
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引用次数: 1
Numerical analysis of isolated end-flattened steel bars under compression in space trusses 空间桁架中孤立端扁钢筋受压的数值分析
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2022-12-21 DOI: 10.3221/igf-esis.63.21
Henrique de Araujo Rosa Cruz, Luciano Mendes Bezerra, Welington Vital da Silva, Ramon Silva
This research aims to characterize the behavior of isolated end-flattened steel bars under compressive loading, in which global instabilities or excessive local deformations represent a significant part of the causes of structural collapse. The association of numerical analyses using the finite element method (FEM) with previously collected experimental data is performed, and their respective results are the core object of critical analysis in this work. Numerical simulations are based on the modified Riks method, complemented in part by modal analysis, whose results demonstrate the occurrence of the aforementioned failure modes in prototypes with slenderness ratios varying in the spectrum from 20 to 200. Finally, the analytical formulations that describe the phenomenon from the approach of global and local instabilities incorporated into current normative expressions are applied in a comparison with the results gathered in the numerical approach.
本研究旨在描述孤立端扁平钢筋在压缩荷载下的行为,其中整体不稳定性或过度局部变形是结构倒塌的重要原因。使用有限元方法(FEM)进行的数值分析与先前收集的实验数据相关联,其各自的结果是本工作中临界分析的核心对象。数值模拟基于改进的Riks方法,部分辅以模态分析,其结果表明,长细比在20至200范围内变化的原型中出现了上述失效模式。最后,将从全局和局部不稳定性方法中描述这一现象的分析公式纳入当前的规范表达式中,并与数值方法中收集的结果进行比较。
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引用次数: 0
Mechanical, Wear, and Fracture Behavior of Titanium Diboride (TiB2) - Cerium Oxide (CeO2) Reinforced Al-6061 Hot-rolled Hybrid Composites 二硼化钛(TiB2) -氧化铈(CeO2)增强Al-6061热轧复合材料的力学、磨损和断裂行为
Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY Pub Date : 2022-12-21 DOI: 10.3221/igf-esis.63.22
S. R. Sreenivasa Iyengar, D. Sethuramu, M. Ravikumar
Development of aluminium composites by stircasting technique is an effective method for fabrication of better quality of MMCs. Stircasting technique is one of the most commonly accepted techniques. In this research work, Al6061 / TiB2+CeO2 hybrid MMCs have been fabricated with varying wt. % of TiB2 (2.5%, 5%, 7.5% and 10%) particulates and constant 5% of CeO2 particulates. The monolithic alloy and hybrid composite were hot-rolled at a temperature of 515°C. Whereas, both the monolithic and hot-rolled hybrid composite was subjected to micro-structural study, hardness and tensile test. Optical microscope analysis revealed uniform dispersal of hard particles with in the base matrix in case of both of ascast and hot-rolled composites. Both ascast and hotrolled hybrid composites have shown extensive enhanced mechanical behavior and high wear resistance when compared with monolithic alloy. Though, ductility of the hybrid MMCs decreased with increasing TiB2 and CeO2 content. A tensile and wear fractography outcome shows the internal fractured structure of a tensile and wear specimen which was analysed using a SEM analysis.
利用搅拌铸造技术制备铝基复合材料是制备高质量MMCs的有效方法。Stircasting技术是最常用的技术之一。在这项研究工作中,用不同重量%的TiB2(2.5%、5%、7.5%和10%)颗粒和恒定5%的CeO2颗粒制备了Al6061/TiB2+CeO2杂化MMCs。整体合金和混合复合材料在515°C的温度下热轧。然而,对单片和热轧混杂复合材料进行了微观结构研究、硬度和拉伸试验。光学显微镜分析显示,在铸造和热轧复合材料的情况下,硬质颗粒在基体中均匀分散。与整体合金相比,铸轧和热轧混合复合材料都表现出广泛增强的力学性能和高耐磨性。然而,混杂MMCs的延展性随着TiB2和CeO2含量的增加而降低。拉伸和磨损断口分析结果显示了使用SEM分析的拉伸和磨损试样的内部断裂结构。
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引用次数: 2
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Frattura ed Integrita Strutturale
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