Types Of Fasteners Research Articles

Graphene nanoparticle effect on flexural and shear behaviors of adhesively bonded single lap joints of GFRP composites

Adhesive bonded joints of fiber-reinforced polymer structural components provide countless benefits; these include great strength and large hardness-to-weight ratios, good fatigue and corrosion resistance, and high energy absorption capability, all of which make them more influential in comparison with other types of fasteners. In this study, the effect of various contents of graphene nanoparticle (GNP) in the epoxy adhesive on the shear and flexural behaviors of glass fiber-reinforced polymer plates (GFRP) bonded joints are investigated. Based on the weight content of epoxy graphene, nanoparticles were added by 0.1, 0.2, 0.3, 0.4, and 0.5 wt.%. GFRP were used as adherents. Failure mechanisms were analyzed by taking photos over the front and rear sides of the samples after tests. The obtained results showed that 0.3 wt.% graphene nanoparticle addition exhibiting the better load transferring between adherents had 145% improvements in shear strength. Furthermore, the samples containing 0.2 wt.% GNP resulted in an increase in flexural strength by 100%.

An Ontology-Based Method for Semi-Automatic Disassembly of LCD Monitors and Unexpected Product Types

Disassembly is a vital step in any treatment stream of waste electrical and electronic equipment (WEEE), preventing hazardous and toxic chemicals and materials from damaging the ecosystem. However, the large variations and uncertainties in WEEE is a major limitation to the implementation of automation and robotics in this field. Therefore, the advancement of robotic and automation intelligence to be flexible in handling a variety of situations in WEEE disassembly is sought after. This paper presents an ontology-based cognitive method for generating actions for the disassembly of WEEE, with a focus on LCD monitors, handling uncertainties throughout the disassembly process. The system utilizes reasoning about relationships between a typical LCD monitor product, component features, common fastener types, and actions that the system is capable of, to determine 4 key stages of robotic disassembly: component identification, fastener identification, disassembly action generation, and identification of disassembly extent. Further uncertainties in the form of possible failure of action execution is reasoned about to provide new actions, and any unusual scenarios that result in incorrect reasoning outputs are rectified with user-demonstration as a last resort. The proposed method is trialed for the disassembly of LCD monitors and a product unknown to the system, in the form of a DVD-ROM drive.

Finite element analysis of typical fastener type full hall steel tubular scaffolds

Based on fastener type full steel tubular scaffolds of power transmission and transformation project, this paper discusses in detail the establishment process of three-dimensional finite element model, including steel pipes, semi-rigid connections, mass of fasteners and boundary conditions. The stability of scaffold is analyzed and the failure mode of instability and ultimate bearing capacity are calculated. Then the static analysis is carried out to analyze the displacement and axial force response of the scaffold during construction, and finally the measures to strengthen the stability and safety of the scaffolds are given.

ПОБУДОВА І АНАЛІЗ КОМП'ЮТЕРНИХ МОДЕЛЕЙ РЕЗОНАТОРІВ ЄМНОСТЕЙ ТЕХНОЛОГІЧНИХ АПАРАТІВ ВІЗУАЛЬНИМИ ЗАСОБАМИ PYTHON

Annotation. The study of nonlinear oscillations and processes in apparatuses that occur under the influence of complex oscillations presents significant mathematical difficulties. The arising strong nonlinear oscillations can significantly intensify technological processes or cause the destruction of structural elements. Therefore, the problem of using the vibrational energy arising in technological devices naturally matured for a long time both for equipment designers and production technologists. A computer model based on a differential equation for determining the frequencies and forms of bending vibrations of a tubular resonator is proposed. The use of the model makes it possible to visualize the modes and frequency of oscillations for a resonator in the form of a cylindrical part of a technological apparatus of any size. This takes into account the thickness of the walls, the outer and inner diameter of the vessel of the apparatus, and its length. The model takes into account the type of tank fastening with variation in the support stiffness. A distinctive feature of the resulting model is that for the first time an approach was used to solve the differential equation of capacity not by obtaining a numerical solution, but an approach was used that includes obtaining an analytical expression for each waveform with subsequent visualization using Python.

ОЦЕНКА ВЛИЯНИЯ РАБОТЫ РАЗЛИЧНЫХ ТИПОВ РЕЛЬСОВЫХ СКРЕПЛЕНИЙ НА СОСТОЯНИЕ ВЕРХНЕГО СТРОЕНИЯ ПУТИ

The paper considers the one of the most important factors that indirectly assesses the serviceability of rail fastening — a number of arising faults in geometry of rail track. On the initial stage the authors have studied sections of railway track with ARS-4, ZhBR-65Sh and Vossloh rail fastening. In result of the study, the authors have got dependencies and made conclusions that characterize the serviceability of railway track on sections with specified types of rail fastening.

Effectiveness of Intermediate Rail Fastenings on the Railway Sections of Siberia

Being one of the important elements of the track superstructure, rail fastenings substantially determine the operational reliability of the rail track and the conditions for its interaction with the rolling stock. The reliability of rail fastenings affects the life cycle cost of the track superstructure. Nowadays, the most common types of rail fastenings on the weldless track are ZBR-65 and ARS-4, and the most promising for difficult operating conditions is ZBR-65PShM. In the conditions of increasing overhaul times, a special task is to identify the optimal type of intermediate rail fastening, which will ensure the stability of the rail track throughout the overhaul cycle with the least amount of labor. It is proposed to use the results of assessing the condition of the rail track with measuring cars, in particular, deviations of the 2nd degree (not requiring speed limits) as a criterion for assessing effectiveness. The assessment was made taking into account the cargo intensity and line plan. The article presents the results of assessing the probability of failure-free operation of rail fastenings for types ZBR-Sh, ZBR-PShM, ARS. Using statistics, particular failures are identified for the elements considered rail fastenings. It has been established that the highest probability of failure-free operation is accounted for by the fastening type ZBR-PShM, and the smallest - by ARS. On the basis of the obtained indicators of the fastening reliability, their durability and current maintenance costs, the most rational area of their application is proposed depending on the line plan and cargo intensity.

Dynamic characteristics of pilot boards of structures

This work is devoted to studying the issues of vibrations of pile foundations, taking into account soil conditions for various types of fastening of piles to structures and the development of rational methods for choosing the parameters of piles and their number in earthquake-resistant construction. Based on the results of theoretical studies, resonance curves were constructed for three types of fastening of the "structure-group of piles" system. A special technique was proposed, and a series of field tests were carried out to determine the amplitude-frequency characteristics of the system.

Металлические застежки богослужебных книг новосибирских старообрядцев

The article analyzes the newly discovered monuments of the Old-Believer book and artistic culture—fasteners of old printed and manuscript liturgical books of the 18th-19th centuries. In 1990s, these fasteners were kept in a small box in a prayer house of the Old-Believers of the Fedoseevsky community in Novosibirsk. It was strictly forbidden to keep service books open, which is observed up to the present time (explanation: “so as not to defile something unclean”). For this reason, books were closed and snapped into place. Observations of the way of life of the Novosibirsk Old-Believers-Fedoseevites allowed us to conclude that the community members treated not only books, but also metal fasteners as sacred objects. The tradition to snap liturgical books continued to live in the years of the USSR until the end of the 1990s, when the community ceased to exist due to the demolition of the prayer house. As a result of the analysis, the classification of the types offasteners, depending on the shape, ornaments and execution technique, was carried out. Some general patterns of ornamentation of fasteners are identified, possible vectors of cultural contacts that influenced the design (medieval Russia and the Middle East) are indicated, and the author’s interpretations of religious meanings imprisoned in the ornaments of these works of applied art are provided. The need to protect objects of worship and everyday life from “evil”, the depicted ornamentalfigures allow us to assume precisely the apotropic (protective) purpose of the fasteners under consideration. Paradoxical as it may seem, the discovered materials also make it possible to draw a parallel with the well-known ancient Slavic archaeological materials, attributed by archaeologists to Pagan amulets.

Screw detection for disassembly of electronic waste using reasoning and re-training of a deep learning model

Growing populations, increasing standards of living, and reliance on advancing technologies are resulting in an emerging abundance of electronic waste. Automating disassembly of these electronic products is a vital part of improving end-of-life product treatment where hazardous chemicals and materials are present. Furthermore, non-destructive disassembly is ideal to preserve the embodied energy in components from manufacturing. This requires the removal, and hence detection, of fasteners like screws in a disassembly environment. Crosshead screws are a common fastener type used in LCD monitors. This paper proposes a method of screw detection for disassembly and presents results of detection of crosshead screws on components of various models of LCD monitors in a disassembly cell. The system first applies gamma correction to standardize brightness––or luminance–– of images. Generic knowledge about screw features in the form of a deep learning model is then used to visually detects screws. The results are analyzed against common screw location combinations on product components in order to logically reason about possible undetected screws that are also likely to exist. Finally, true negative detections are collected as new training data and the deep learning model is re-trained on these missed detections to improve performance; tailoring and adapting to the environment of the specific disassembly cell.

Methodology for the assessment and refinement of friction-based dissipative devices

An innovative dissipative system for the seismic upgrade of historical buildings is presented. The system comprises a friction-based dissipative device able to provide energy dissipation capacity to connecting walls. To verify the compliance of the device’s initial prototype with the relevant European Standards, a testing and design methodology is developed. This optimisation approach consists of: two tests loops, to identity the dependence of the dissipative device on bolt preloading, type of fasteners, frictional interfaces and environmental conditions; and a design loop where advanced 3D modelling and analysis are used to improve the design according to the experimental results. The performance is measured by variation of effective damping. This iterative procedure singles out parameters that need improvement and allows to produce two new prototypes, differing by shape and frictional interfaces. The revised prototypes prove to deliver a reliable response to cyclic loading, containing the variation of effective damping well within code requirements, even after exposure to adverse environmental conditions.

Интенсивность накопления остаточных деформаций железнодорожного пути, эксплуатируемого в сложных природно-климатических условиях

Objective: To analyze the results of observations conducted to assess the intensity of the accumulation of residual deformations in the railway track structure operated in severe natural and climatic conditions (the observation site is located above the Arctic Circle). The following were also taken into account: the railway track design (type of intermediate fasteners, track slab, condition of the ballast bed), the railway line scheme, the tonnage handled, the train speed and the axle load. Methods: Mathematical statistics, data processing. Results: The dependences of the railway track deformation and strength properties, including the tonnage handled, have been obtained. Practical importance: The presented observation results of the assessment of the intensity of deformation accumulation in the railway track structure operated in the severe natural and climatic conditions of the North of the Arctic Circle indicate that the use of increased axle load wagons will entail a significant reduction in overhaul life and an increase in the track maintenance operating expenditures

Fastening Strategies to Prevent Galvanic Corrosion

In marine applications aluminum structures are commonly fastened together with stainless steel fasteners. This combination of dissimilar metals causes galvanic corrosion currents which degrade the aluminum structure. The purpose of this research is to develop fastening strategies that will reduce the degradation of the aluminum structure. The impetus for this research is specifically to increase reliability and availability of equipment installed on Navy range craft which operate in the support of training and test and evaluation (T&E) events. Direct fastener substitution would cause the least impact to the overall design of a system reducing alteration costs. Therefore, in this research different types of fasteners were tested to determine their effect on corrosion in the aluminum structure. Fastener types: 316 stainless steel (control), Titanium (Ti-6Al-4V), 316 stainless steel PVD coated with TiN, 316 stainless steel PVD coated with CrN, and 316 stainless steel coated with a Sol Gel. The efficacy of each fastener type was determined by several tests. Samples representing a bolted join in an aluminum structure were assembles using each type of fastener and deployed in a marine environment, after exposure weight loss data was collected. The fasteners were also subjected to cathodic potentiodynamic polarization to determine the kinetics of oxygen reduction and hydrogen evolution on the bare 316 SS, coated 316 SS, and bare Ti-6Al-4V. The cathodic polarization data of the fasteners were compared to that of the anodic polarization data of AA6061-T6. The potentiodynamic polarization data was used to gain an understanding of the galvanic corrosion mechanisms between the fasteners and AA 6061-T6. The results from the polarization experiments were compared to the actual corrosion damage of galvanic couples in the field. Acknowledgements: This material is based on research sponsored by the USAFA and University of Hawaii under agreement number FA7000-18-2-0004. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon.

Experimental Analysis of the Influence of the Fastener Type on the Embedment Strength Parallel to the Grain in Glued Laminated Timber

AbstractEmbedment strength is an important parameter that governs the ductile load-carrying capacity of timber joints with dowel-type fasteners. This property is dependent upon several factors, esp...

Mechanical Joining of Fibre Reinforced Polymer Composites to Metals-A Review. Part I: Bolted Joining.

As the fibre reinforced plastic composites gain larger and larger share in industry, the problem of joining them with metal elements becomes significant. The current paper is the first part of the literature review, which gathers and evaluates knowledge about methods suitable for mechanical joining of composite and metal elements. This paper concerns bolted joining, because this method of mechanical joining is widely used for joining composite materials. The paper describes failure modes of bolted joints in composite materials, the influence of the bolt clamping torque, the clearance between the bolt and the hole and aging on the performance of the joint, drilling techniques used in composite materials in order to minimize damages, different fastener types, inspection techniques, and finally, the techniques that have been developed in order to improve the strength of the bolted joints in composites. Since the hole drilled in a composite material in order to perform bolted joining is a weak point of the structure, those techniques: bonded inserts, titanium foil internal inserts, fibre steering, additional reinforcement, and moulded holes, mainly aim to improve the strength of the hole in the composite. The techniques have been discussed in details and compared with each other in the summary section.

Examination of Ductility and Seismic Diaphragm Design Force-Reduction Factors for Steel Deck and Composite Diaphragms

This paper analyzes the ductility and overstrength of steel deck diaphragms and composite concrete on steel deck diaphragms and computes associated diaphragm design force-reduction factors, Rs. First, a database of past tests on steel deck and composite diaphragms was created, and more than 750 specimens were compiled into the database. A subset of 95 cantilever diaphragm specimens with postpeak inelastic behavior was identified for which specimen ductility and overstrength were calculated. The effects of variables such as fastener type, fastener spacing, and deck thickness on diaphragm ductility are explored. A method is then developed for converting cantilever diaphragm specimen ductility to diaphragm system-level ductility. Finally, diaphragm design force-reduction factors, Rs, are calculated consistent with an accepted methodology to be Rs=2.09, Rs=1.13, and Rs=2.36 for bare deck diaphragms with mechanical fasteners, bare deck diaphragms with welds to the supports, and concrete on steel deck diaphragms, respectively, for cyclically loaded specimens and assuming a long period structure.

Deformations Of Fastenings Of Slopes Of Retaining Structures At Technological Purpose Reservoirs

The article presents the data of field, laboratory and theoretical studies, which made it possible to determine that processing, abrasion destruction of natural shores and loose upstream slopes of dams and enclosing structures, takes place on technological water bodies of Belarus - regardless of their economic use - technical, drinking water supply, regulation of runoff, energy, land reclamation, etc. The period of development of the processing process and the formation of the equilibrium profile is divided into a number of time periods (stages). Three stages are distinguished for the conditions of water bodies in Belarus: initial, intense dynamics and attenuation (equilibrium). Based on the data of field surveys of shore protection structures, the current state of various types of fasteners is assessed with the identification of the causes of their destruction and the extent of deformations. It has been established that the most common shore and slope fastenings are fastenings in the form of reinforced concrete monolithic or prefabricated plates. It is determined that the most widespread are the deformations of the fastenings in the form of the disclosure of inter-tile construction, temperature and settlement joints. As a result of opening the joints of the plates, the destruction and washing out of the sand and gravel bed, the formation of hollows and niches in the body of the slope with its subsequent processing, deformation and destruction of the fastening take place. It should be noted that the destruction of the fastening also occurs in stages, and the stages of the destruction of the fastening coincide with the staging of the processing of loose ground slopes. Based on the data of full-scale and experimental laboratory studies, scientifically substantiated criteria for assessing the stability of soil slopes and slopes with fastening by reinforced concrete slabs are proposed, which can be used to predict the state of designed and operated shore protection structures and fastening slopes. An enlarged methodology has been developed for assessing the risks abrasion of coasts and slopes of retaining structures based on the proposed territorial coefficient of abrasion risk, a mathematical factor model of risk based on the fault tree, and also an experimental electronic map of the risks of abrasion for the conditions of water bodies in the Minsk region of Belarus are developed.

The Effect of Fastener Type (Clamex P14 and Tenso P14) and Adhesive Type on Compression and Tension Performance

In this study, the effects of different fasteners (Clamex P14 and Tenso P14) for medium density fiberboard (MDFLamM) surfaced with synthetic resin sheet wood-based materials as well as several adhesives (PVAc-D4) and PU-D4) on diagonal tension and compression forces, were analysed. In the study, melamine coated medium density fiberboard (MDF-Lam) was used as wood-based material, Clamex P14 and Tenso P14 were used as fasteners and polyvinylacetate (PVAc-D4) and polyurethane (PU-D4) glues were used as adhesive agents. The diagonal tension and compression force tests were applied on 120 pieces of test samples prepared in this respect based on the principles of ASTM D 1037. As a result, The diagonal compression and tensile forces values were found in the highest Clamex P14 fastener and polyvinylacetate adhesive bond (PVAc-D4), the lowest was in the joint with Tenso P14 fastener without any adhesive agent. For L type corner-joints, it is suggested to use Clamex P14 as a fastener and polyvinylacetate adhesive (PVAc-D4) as the type of the adhesive agent.

Effect of beam-deck connection flexibility on lateral torsional buckling strength of wooden twin-beams

Abstract Two finite element solutions are developed for the lateral torsional buckling analysis of timber beam-deck assemblies consisting of two beams braced by decking through fasteners. In contrast to past solutions, both solutions capture the rotational flexibility provided by the connections between the deck boards and the beams. The first solution is intended for systems with partial lateral restraint provided by the deck boards allowing lateral sway while the second solution is intended for systems that are restrained from lateral movement at the deck level. An experimental program is conducted to quantify the rotational stiffness of beam-deck connections for different types of fasteners and the results are input into the finite element formulations to evaluate the corresponding buckling capacities for beam-deck systems. The results indicate that the buckling capacity of beam-deck systems can be significantly increased with commonly used fasteners while high-capacity fasteners can achieve buckling capacities nearly identical to those where rigid rotational connections are assumed.

Study on fatigue life of ballastless track fastener springs based on a fatigue test

Purpose Fastener technology is one of the key technologies of the ballastless track structure, and the spring strip is the key component to realize the fastener function. Based on the fatigue test of the WJ-7 type fastener of the ballastless track in China, it is concluded that the fatigue damage of an elastic strip is the main reason for the decline of service performance of the fastener. The purpose of this paper is to discuss the fatigue life of the fastener. Design/methodology/approach First, a DH3818 static strain tester is used to measure the static strain signal in the elastic strip fatigue test, and then the fatigue limit of the WJ-7 elastic strip is calculated. Finally, the fatigue life of the fastener strip is estimated. Findings The findings of the paper are as follows: first, the lowest fatigue life with a survival rate of 99 percent should be taken as a reference for the service times of WJ-7; second, the fatigue life of the modified formula found to be short under the same stress amplitude. Originality/value The fatigue test is processed by the authors and the results of elastic strip are obtained based on the test. Meanwhile, the corresponding limit value of the fatigue stress amplitude is calculated based on the tested results.

Composite Underrail Basements. Constructions

The article summarizes the world experience in the use of sub-rail bases (sleepers, bridge and switch ties), including their traditional structures made of wood, steel and reinforced concrete, as well as innovative composite structures (plastic, composite) based on polymer binders. The types of structures of composite sub-rail bases that have found application or are at the stage of practical implementation, their features of operation on the railway, the types of fasteners used, as well as typical defects of such structures are generalized. A classification of structures of composite sub-rail bases is proposed. The history of evolution and trends in their development, which can serve as a valuable guide for optimizing structures, expanding their production and application in railway transport, are discussed. Based on the analysis of more than 120 literature sources, it is concluded about the advantages of composite sub-rail bases in technical, economic and environmental aspects as the resource and environmental crisis worsens, in which the use of composite sub-rail bases becomes a promising direction for the development of the railway industry. Keywords: structures of composite sub-rail bases, types of fasteners used, structural defects, railway tracks, sleepers, railway transport.