Outer Reinforcement Research Articles

The Strengthen Muallaf Resourches Through Development of Local Creative Economi Potential

Abstract. A proselyte (muallaf in Islam) has a condition of vulnerability that is still unstable in religion. This is a condition that still does not have a solid faith because their understanding of religion is still low, or strong environmental and economic temptations are often used as weapons by missionaries. Conversion of religion is a necessity in society, therefore religious teachings become something that is very important to be known and explored by a follower of its religion (aqidah), so that a muallaf will not be able to easily change their belief to other religions. However, it cannot be denied that the migration of an adherent of a religion to another religion can also be caused by other factors such as social, economic, political, cultural conditions, and so on. For this reason, in this advanced empowerment program, after strengthening the religious aspect, it is also important to intersperse with activities related to the creative economy that can be explored by converts. This effort to extract creative economic power is by utilizing materials from natural resources in their environment, such as banana blossoms, or also other plants that can be processed to become more usable for the community. This advanced empowerment program is expected to be able to motivate community creations in developing creative economic potential which is hoped to become a potential for their economic empowerment in the future so that they have the resilience to be independent from an economic point of view and are not easily influenced by incitement or lures to change their beliefs. The empowerment program between religious studies and the provision of additional knowledge is packaged in one time and place because of course the most important focus is a religious study but packaged with additional activities. It is hoped that it can increase their enthusiasm to always be present in every activity, and provide an impact on their economic power directly so that they can provide inner and outer reinforcement.

Issues of Developing Equal-Strength Two-Layer Spherical Rubber-Metal Hinges

Development of equal-strength two-layer spherical rubber­metal hinges (RMH), described in the paper, is associated with the problem that with an equal thickness of the layers of rubber bushings and an equal opening angle, there is a significant difference in their radial stiffness and relative deformation of the rubber. With hinge dimensions corresponding to those of the hinges used in the undercarriage of locomotives, there is a difference in relative deformation of inner and outer bushings by about 1,5 times. As a result, it is proposed to determine the load capacity of spherical two-layer RMH by the value of relative deformation of the rubber of the most loaded bushing. Also, studies have been carried out on the possibilities of creating a uniformly deformable design of a spherical two-layer RMH.To determine the characteristics of a spherical rubber-metal hinge, applied digital computer modelling based on the finite element method. A proposed parametrised geometric model of a spherical two-layer RMH and a finite element model of an elastic bushing offer the ratio of radial stiffnesses of outer and inner bushings, which is close to the preliminarily determined one, based on the equations of the theory of elasticity in displacements in a spherical coordinate system.It has been established that to achieve uniform elasticity by changing the opening angle, the opening angle of the outer reinforcement of RMH should be approximately 1,5 times less than the opening angle of the inner one. This makes it possible to reduce the width of outer reinforcement of RMH by 25 % but raises the problem of strength and rigidity of outer edges of intermediate reinforcement. Also, equal elasticity of hinge bushings can be achieved due to their different thicknesses, while to achieve non-uniform stiffness of bushings within ± 5 %, it is required to ensure that deviation of the intermediate cage diameter during hinge manufacture is less than ± 0,1 %.The obtained research results prove the practical possibility of creating an equally strong (with equal bushing rigidity) spherical two-layer RMH. The issue of searching for a compromise design of RMS, acceptable from the point of view of loading of the intermediate cage and of the requirements for manufacturing accuracy, requires further study.

Repair Parameter Design of Outer Reinforcement Layers of Offshore Wind Turbine Blade Spar Cap Based on Structural and Aerodynamic Analysis

The influence of the outer reinforcement layers on the repair structure and aerodynamic performance was studied. Firstly, a continuous damage mechanics model was established, and the 3D Hashin criterion and cohesive zone material model were used to analyze the damage repair model. The failure load deviation was 5.5%. Secondly, on the basis of the γ−Reθ transition model and SST–ω turbulence model, the aerodynamic analysis model of DU300 airfoil was established. The numerical simulation results showed that the lift coefficient and pressure distribution at the angle of attack of 10° and 15° were deviated from the experimental values by 2%. Furthermore, 27 structural repair models, nine 2D aerodynamic repair models, and a 3D full-scale blade model were designed. It was found that, when the repair length accounted for 60% of the total model length, the failure load increased by 22%, but the aerodynamic power with the repair length of 10 m was decreased by 0.137%. When the repair area was large and the repair height was from 4 mm to 6 mm, the failure load was greatly increased by about 30%, and the aerodynamic pressure distribution and static pressure field fluctuated significantly. The results show that the structural and aerodynamic characteristics were closely related to the repair parameters.

Torsional structural behavior of composite rubber hose for offshore applications

Composite offshore rubber hose is a key component for offshore oil transfer. In this work, structural behavior of the offshore rubber hose under torsion is studied. A detailed nonlinear finite element model with rebar technique for offshore rubber hose is established, considering the nonlinear material properties and interactions between components. The effects of different winding angles of cords, the pitches of wire helices and the directions of torsion on hose mechanical performance are studied. The finite element model is validated by the test data and can be a predictive tool for the structural performance of rubber hose under torsion. The results show that the forces in the odd numbered cord layers and the even numbered cord layers are totally different and the pitches of the helix wire and the angles of the cords have a great influence on the torsional stiffness of the rubber hose. Also, when the rubber hose is twisted in the clockwise and anti-clockwise directions, the mechanical properties of inner reinforcement plies and outer reinforcement plies are different and the torsional stiffness displays a nonlinear trend. The effects of some design parameters on the torsional stiffness of the hose are investigated and a prediction formula is obtained. This work can provide theoretical basis and calculation methods for the structural design and integrity evaluation of stiffened composite rubber hose.

Effect of reinforcement parameters on the impact resistance of cementitious composites for vehicle restraint systems

The presented study investigates the dynamic resistance of cement-based large-format elements with various types of reinforcement and retrofitting. Both inner and outer reinforcement has been assessed. The effect of matrix type (low, high, and ultra-high-strength), amount of steel fibres, and ribbed reinforcing steel on impact toughness has been evaluated. The influence of an additional polymer-based layer to increase impact resistance level has also been investigated. The effectiveness of each reinforcing method has been compared. An large-scale impact hammer device KYV-I-2020 (up to 1100 J) has been used to determine the impact toughness. The results show that ribbed reinforcing steel increases the impact toughness more effectively than the fibre reinforcement, steel mesh and additional polymer layer. However, fibers significantly reduce fragmentation, especially at a higher concentration of 2.5 vol%, contributing to the overall higher impact resistance of the elements and their safety in practical use. The test results also show a significant effect of the matrix type, with the most increased impact toughness achieved when using a high strength matrix. The addition of an antifragmentation polymer layer then provides a further increase in impact toughness. The results also indicate that similar resistance capacity can be achieved using different reinforcement combinations, which is crucial for designing the material composition with the optimal performance/cost ratio. The presented research is a part of the development process of the restraint systems for stopping trucks. The data obtained has been used to create the elements with suitable composition; their effectiveness has been successfully verified by numerical simulations and real tests.

Improving the bonding of polyethylene to E-glass/epoxy composites using ultraviolet irradiation

One of the problems in type-IV pressure vessels (composite pressure vessels with a thermoplastic inner liner) is the quality of bonding between the liner to the outer reinforcement layer. In the present research, the effect of the ultraviolet (UV) irradiation on the surface of the high-density polyethylene (HDPE) for the co-bonding process of E-glass/epoxy composites to HDPE liner was investigated experimentally. To recognize the effect of the UV irradiation on the surface properties, the contact angle measurement, and the atomic force microscopy (AFM) were performed. Asymmetric double cantilever beams (ADCB) tests were conducted to determine the strain energy release rate (SERR) as a factor indicating the crack resistance of the joint. According to the results, it was found that 20 min of UV irradiation exposure time presented the lowest contact angle on the surface of HDPE, and the highest strain energy release rate in ADCB specimens. The result of the tensile test for HDPE under the UV radiation demonstrated less than 8% degradation in the mechanical properties. Therefore, it can be concluded that 20 min of UV irradiation exposure time could be used as a surface treatment of the HDPE liner of type-IV pressure vessels.

Collapse analysis of a large plastic pipe using cohesive zone modelling technique

Polypropylene (PP) plastic pipes have recently gained widespread application in non-pressurized gravity pipes used for seawater intake lines in the petrochemical industry. These pipes consist of a solid wall base pipe, on which an outer reinforcement called the omega-profile is spirally winded and hot fusion bonded. The omega-profile is usually filled with grout to provide on-bottom stability for subsea installation. It is of high importance that the bond between the omega-profile and the base pipe has sufficient strength to provide resistance against buckling of the pipeline system. The objective of this study is to investigate the collapse behaviour of such large-diameter PP pipes subjected to a negative internal pressure. The bond is modelled with cohesive zone modelling technique with the aim to determine the failure mode that governs the collapse behaviour of the pipe, e.g. buckling or delamination. Experiments where conducted on single cantilever beam (SCB) specimens cut from the pipe to determine the cohesive bond strength between the omega-profile and base pipe. The findings from the experiments are implemented in a full pipe model, where the surface between the omega-profile and base pipe is assigned bond strength characteristics in accordance with the experimental results. The FEA results of the non-linear collapse analysis of the full pipe model show that for the range of grout stiffness values considered (0 ≤ Eg ≤ 30 GPa), the governing failure mode of the pipe is initiated by buckling and proceeded by delamination. For delamination to govern the failure mode, a grout stiffness greater than 36 GPa in combination with a weaker bond strength than the experimentally measured would be required. The methodology presented in this study gives a rather accurate tool for the design and analysis of this type of structures, and can reliably assess the bond strength level required in view of the governing failure modes, e.g. buckling and delamination.

Structural performance of novel SCARC column under axial and eccentric loads

A novel spiral confined angle-steel reinforced concrete (SCARC) column was developed in this study. A total of 16 specimens were prepared and tested (eight of them were tested under axial loading, the other eight were tested under eccentric loading). The failure processes and load-displacement relationships of specimens under axial and eccentric loads were examined, respectively. The load-carrying capacity and ductility were evaluated by parametric analysis. A calculation approach was developed to predict the axial and eccentric load-carrying capacity of these novel columns. Results showed that the spiral reinforcement provided enough confinement in SCARC columns under axial and low eccentric loads, but was not effective in that under high eccentric loads. The axial load-carrying capacity and ductility of SCARC columns were improved significantly due to the satisfactory confinement from spirals. The outer reinforcement and other construction measures were necessary for SCARC columns to prevent premature spalling of the concrete cover. The proposed calculation approach provided a reliable prediction of the load-carrying capacity of SCARC columns.

SHEAR CAPACITY PREDICTION FOR STIRRUP-CORRODED RC BEAMS STRENGTHENED WITH FRP

Corrosion of steel reinforcement represents one of the main causes of deterioration and degradation of reinforced concrete (RC) structures. Shear reinforcements (stirrups) as an outer reinforcement in RC beams are more susceptible to corrosion problems and damage. This paper describes an analytical procedure for predicting the shear capacity of stirrup-corroded RC beams strengthened in shear using FRP laminates. The procedure shows how to incorporate the effects of the damages due to corrosion of stirrups into the design equations. An experimental investigation has been conducted to provide experimental data on the shear capacity of RC beams with corrosion-damaged stirrups strengthened using carbon fiber reinforced polymer (CFRP) sheets. The experimental study comprised three beams of 200 mm wide, 350 mm deep, and 2800 mm long. The steel stirrups in the beams were corroded using an accelerated corrosion technique. After CFRP strengthening, the beams were tested in four-point bending under a simply supported span of 2400 mm. The shear capacity of the strengthened beams was predicted using the proposed procedure and compared with the experimental ones. Good correlations were found between the predicted and experimental shear strength of the beams.

Efficiency of the confinement reinforcement in anchorage zones of posttensioning tendons

In order to study the efficiency of the confinement reinforcement in anchorage zones of posttensioning tendons, using both ordinary reinforced concrete (ORC) and high‐performance fiber reinforced concrete (HPFRC), an experimental research has been performed on the bearing strength of concrete prismatic specimens. This research also intended to assess both ultimate capacity and adequate serviceability of the local anchorage zone when reducing the concrete cross section and the confining reinforcement, both specified by the anchorage device supplier, by using an HPFRC. The experimental program included ORC prismatic specimens with 305 mm × 305 mm × 650 mm reinforced with spirals and a combination of spirals and stirrups, and HPFRC specimens with 210 mm × 210 mm × 420 mm reinforced with stirrups. The reinforcement steel strains were measured to monitor the steel yielding, to assess the relation between the strains of the inner (spiral) and outer (stirrups) levels of reinforcement and the uniformity of the confinement forces along the confined length. A comparison between the bearing strength obtained by experimental tests and by models found in the literature is also presented. From the strain measurements, it can be concluded that in the case where there are, simultaneously, two types of confinement reinforcement, the outer reinforcement is not as effective as the inner one. Therefore, when computing the bearing strength, the linear superposition of contributions of both spiral and stirrups for confinement can be nonconservative, leading to too high estimated load capacity.

Визначення впливу форми поперечного перерізу стиснутих залізобетонних елементів на ефективність їх підсилення зовнішнім армуванням композитними полотнищами

Визначення впливу форми поперечного перерізу стиснутих залізобетонних елементів на ефективність їх підсилення зовнішнім армуванням композитними полотнищами

Bending and lateral crushing behavior of a GFRP and PA6 reinforced aluminum square tube

Abstract In this study, the bending behavior of a thin-walled aluminum square tube (AST) were analyzed using the finite element (FE) method, and reinforcing arrangements were decided for the composite beams based on the FE results. Accordingly, bending behavior of thin-walled ASTs with internal cast polyamide (PA6) and external glass fiber reinforcement polymers (GFRP) were investigated via a quasi static three-point bending test experimentally. Moreover, bending performance under impact loading was also investigated experimentally. The results revealed that local buckling has a decisive influence on bending performance of the tube, and the contribution of inner reinforcement is more effective than outer reinforcement. The reinforcements provide 575 % and 312 % increases in bending load and impact energy, respectively. The developed plastic-metal hybrid-composite structure is promising especially for critical supporting parts in vehicles. It is thought that the combination of these materials will offer new focus of attention for designers seeking more appropriate composite beams with high bending load and impact resistance.

Burning of Mixtures of Copper Oxide with Titanium

This paper describes the study of the effect of physical and chemical properties of powder titanium and the equivalence ratio on the burning parameters of its mixtures with copper oxide. It is shown that the linear burning rate of such mixtures is significantly dependent on the brand of used titanium. Under normal conditions, the mixtures can stably burn with the content of copper oxide of not smaller than 13%. With an increase in the content of copper oxide to a stoichiometric ratio, there is a change of combustion regimes: multifocal, multifocal with detachment of solid residue, combination of convective and multifocal, multifocal with melt formation, flaming combustion, and fireball. It is determined that, in this system, there may be convective burning under atmospheric pressure in the absence of outer reinforcement.

To the rationalization of the constructive solutions of the bridge supports

Reduction of material consumption and labor intensity of building structures is a topical task for both theory and practice of building production. Today there are many ways to achieve proper economic effect while reconstruction or erection of building and structures. One of them is to rationalize well-known constructive solutions using as criteria the value of density of potential energy of deformation of structures. In this connection, the new constructive solution for short massive supports with outer reinforcement made of expanded metal sheet and frames (reinforcing rings) which are used in construction of road and railway bridges and high-rise buildings is proposed in this paper. The theoretical approach for the definition of its rational parameters is given. Numerical analysis of the highlighted method is also carried out. As a result of study the increase in the bearing capacity in concrete pillars made in rational mesh clips with and without frames was obtained.

Endocardial linear infarct exclusion technique for infarcted lateral wall.

We report a novel method of surgical ventricular restoration for an infarcted lateral wall: the endocardial linear infarct exclusion technique. First, transmural ventriculotomy is performed at the centre of the scar longitudinally along the coronary artery. Second, the inner layer is sutured in a longitudinal direction with 4-0 polypropylene continuous sutures to approximate the border between the normal and infarcted myocardium. Finally, the outer layer is closed with a combination of interrupted buttress and continuous over-and-over sutures with outer felt reinforcement. The advantages of endocardial linear infarct exclusion technique are as follows: the risk of bleeding is low; it is not technically demanding and is reproducible; the coronary artery can be preserved; approximation of the base of the anterior and posterior papillary muscles is possible in the case of ischaemic mitral regurgitation and it can also be applied to the anterior and inferior walls.

Acute onset of intracranial subdural haematoma 2 days after spinal anaesthesia.

Sir, Spinal anaesthesia (SA) is widely used for surgeries but serious complication such as intracranial subdural haemorrhage (ICSH) can rarely occur.[1] The incidence of ICSH after SA has been reported to be 1 in 500, 000.[2] During literature review, 35 cases were identified, and most had a chronic course and associated with post-dural puncture headache (PDPH).[1] We report a case of acute onset of ICSH 2 days after SA with no history of trauma. The 21-year-old young male presented with fistula in ano, and was scheduled for an elective surgery in our hospital. Patient belonged to American Society of Anaesthesiologists physical status 1 with no comorbid conditions. He had no history of any pre-existing brain pathology. The anaesthetic procedure was completed with ease in a single attempt with lumbar puncture at the L 2/3 level using 25-gauge Quincke's needle; there was free flow of clear cerebrospinal fluid (CSF) and 0.5% heavy bupivacaine was injected. T12 level of block was achieved, and surgery completed uneventfully. On 2nd post-operative day patient suddenly developed severe headache, and 2 h later he developed generalised tonic clonic seizure and became unconscious. Patient was immediately intubated and administered intravenous phenytoin and mannitol as advised by neurologist. Computed tomography (CT) scan was obtained, which showed right subdural haematoma (SDH) with midline shift of 1.3 cm [Figure 1]. Patient was shifted to operation theatre where craniotomy with evacuation of haematoma was done. Post-craniotomy, patient was shifted to neuro-intensive care unit and after 48 h of ventilator support, was extubated. On the third post-operative day, non-contrast CT was done, which showed complete resolution of SDH [Figure 2]. Post-operatively during his stay in hospital patient remained apathetic and aphasic for which psychiatrist opinion was taken, and he advised thyroid function tests. He was found to be hypothyroid and hence he was put on the tablet thyroxine 100 μg once daily. On 7th post-operative day, sutures were removed, and wound was found to be healthy. On discharge, patient was conscious with left residual hemiparesis. He was discharged on Ryle's tube feed and indwelling Foley's catheter. Fifteen days later, his left residual hemiparesis resolved and his Glasgow coma scale became 15. Sixty days later patient came back to our hospital for duraplasty, which was done, and he was discharged after 3 days.Figure 1: Right acute subdural haematomaFigure 2: Computed tomography scan after evacuation of right acute subdural haematomaVery few data exist about the consequences of SA-induced ICSH. As symptomatology frequently mimic PDPH, a number of them are frequently missed.[3] According to the literature, its prevalence ranges between 1/500,000 and 1/1,000,000.[45] A Swedish retrospective study published in 2004 and covering a decade (1990–1999) mentions 127 cases of neurological complications following SA, of whom the risk was assessed to be 1/20,000–1/30,000, among which two cases of SA-ICSH were reported.[6] A French study reported 4 such cases of SA-ICSH over a period of 9 years in a medium size centre.[7] The physiopathogenic mechanisms of SA-ICSH are poorly understood. A leak of CSF at the level of arachnoid tear probably induces a lowering of intraspinal and intracranial pressure. The resulting dynamic alteration of CSF flow leads to a relative ventricular collapse and a rostrocaudal movement of central nervous system. As a consequence sensitive meningeal structures or meningeal pain sensors, cranial nerve and bridging-veins that link the encephalon to the meninges and drain into the dural sinuses are stretched.[8] Electron microscopic data on human bridging veins show thin walls of variable thickness, circumferential arrangement of collagen fibres and lack of the outer reinforcement by arachnoids trabecules. All these render the subdural portion of the vein more fragile than its subarachnoid portion. These features explain the laceration of veins and the subdural location of resulting haematomas, which can evolve in various ways, acute or chronic. Cerebral SDH is a serious complication of SA that must be kept in mind and may mimic PDPH. History of lumbar puncture, prolonged non-postural PDPH and development of neurological symptoms should be regarded as a warning sign of an intracranial haematoma and initiate immediate diagnosis and treatment of the same.

Strut and tie modeling for RC short beams with corroded stirrups

Corrosion of steel reinforcement is one of the major problems that shorten the service life of reinforced concrete (RC) structures. Steel stirrups, due to their location as an outer reinforcement, are more susceptible to corrosion problems and damage. However, there is limited research work in the literature on the effects of stirrup corrosion on the shear strength of RC beams. This paper attempts to evaluate analytically the residual shear strength of RC short beams with corrosion-damaged stirrups. The shear strength of short or deep beams are generally determined using the strut and tie model. The corrosion effects were implemented in the model to make it capable of predicting the residual shear capacity of RC beams with corroded stirrups. The effect of corrosion is implemented considering the reduction in geometry of the concrete cross section due to spalling and reduction in effective compressive strength of concrete due to corrosion cracks. The proposed strut and tie model which accounts for the corrosion effects was verified using the experimental data available in the literature, and good agreement was found.

Bending response of hybrid composite tubular beams

The influence of inner and outer reinforcements on the bending performance of a thin walled aluminum tube was investigated. Polymeric materials (PA6, PP) and glass/carbon fiber reinforced epoxy were considered to form the composite beam for the inner and outer reinforcement, respectively. The experimental results indicated that the outer reinforcement with a [02/903] fiber orientation layout increased the collapse load by a factor of 4.5 and 5.3. In the hybrid composite beam (HCB), load carrying capacity (LCC) increased a maximum of 14 times. Load carrying capacity of HCB is 2.5 times higher than the steel tube that is used in automotive industry.

굽힘 붕괴 성능 향상을 위한 센터 필라 설계

High bending collapse performance (maximum resistance force and mean resistance force) of body center pillar is an important design target for vehicle safety against side impact. In this study, effect of the upper section shape and the thickness of outer reinforcement on bending collapse performance was investigated for the center pillar of a large passenger car. First, through bending collapse analyses using simple models with uniform section, an optimized center pillar upper section was chosen. Next, bending collapse performance for various models of the actual center pillar with changing the thickness of outer reinforcement were analyzed. The finally designed model showed distinctive enhancement in bending collapse performance nearly without weight increase.

The profiled flooring is used during the reconstruction and repair of small bridges

The review of plate span structures constructions is carried out. The perspectiveness of application of plate span structures with outer reinforcement in the form of profiled steel sheets is paid attention to. The distributive capacity of plate span structures with application of profiled steel sheets is investigated.