Mechanical Splicing Research Articles

Experimental Study on Flexural Performance of lap-spliced and mechanical-spliced (clamp type) rebars in RC Beams

Various methods can be employed to splice reinforcement bars, including lap splicing, welding, and mechanical splicing. Lap splicing is the most used method among these techniques. However, this study primarily focuses on evaluating the potential of mechanical splicing to replace the lap splice method. The investigation involved assessing the flexural performance of six RC beams in a series of laboratory experiments. These beams represented a control beam, an RC beam with lap-spliced rebars, and an RC beam with clamp-type mechanical spliced rebars. The laboratory testing results indicated that the RC beam with lap-spliced rebars had the highest load-bearing capacity, resulting in the highest nominal flexural moment (Mn). In contrast, the control beam demonstrated the highest deflection, signifying a greater level of ductility. However, RC beams with mechanical splices (clamp type), while not achieving the highest flexural moment and ductilities, are still competitive, as the experiment revealed that the difference is not significant. Consequently, it can be concluded that mechanical splicing has the potential to compete with or replace lap splicing in RC beams.

New hallmarks of ageing: a 2022 Copenhagen ageing meeting summary.

Genomic instability, telomere attrition, epigenetic alterations, mitochondrial dysfunction, loss of proteostasis, deregulated nutrient-sensing, cellular senescence, stem cell exhaustion, and altered intercellular communication were the original nine hallmarks of ageing proposed by López-Otín and colleagues in 2013. The proposal of these hallmarks of ageing has been instrumental in guiding and pushing forward research on the biology of ageing. In the nearly past 10 years, our in-depth exploration on ageing research has enabled us to formulate new hallmarks of ageing which are compromised autophagy, microbiome disturbance, altered mechanical properties, splicing dysregulation, and inflammation, among other emerging ones. Amalgamation of the ‘old’ and ‘new’ hallmarks of ageing may provide a more comprehensive explanation of ageing and age-related diseases, shedding light on interventional and therapeutic studies to achieve healthy, happy, and productive lives in the elderly.

Effects of Different Splicing Methods on Conveyor Belt Strength

Conveyor belts are mechanisms that provide continuous transfer of any product from one place to another. Belt conveyor systems are at the forefront of the systems that minimize the need for people in the transportation of materials. In this way, it is inevitable to achieve both time and cost savings. With the continuous development of today's technology, it develops in the improvements in belt conveyor systems. Owing to the innovations and improvements in the conveyor belts, it becomes possible to minimize the maintenance, repair and undesired stoppages of the facilities. In this study, specimens extracted from a conveyor belt with a width of 800 mm, with a tensile strength of 45 N/mm2, 4 layers of polyester-polyamide blend cord fabric, 6 mm rubber bottom coating thickness and 3 mm rubber top coating thickness were used. The specimens were taken in three different ways (from the unspliced belt, from the mechanically spliced belt and from the vulcanized belt). The specimens taken from the spliced conveyor belts were subjected to the tensile test. The strength values of the belt specimens, from high to low, are in the form of unspliced belt, vulcanized belt and mechanically spliced belt. Among these applications, it has been observed that the mechanical splicing method is easier in terms of application than other splicing methods. It has been observed that the time required for maintenance and repair of the mechanical splicing method is between 1 and 2 hours, and the time required for the splicing method with vulcanization is between 6 and 8 hours. It has been understood that the mechanical method is advantageous over the vulcanization method in terms of the application time of the belt splicing method.

Al 케이블 접속부 열특성에 따른 접속시공 최적 방안 연구

The causes of joint overheat problems are included in the mechanical splicing processes. In this paper, an analysis and examination of the cable joint process are conducted in comparison with typical types of connectors and various processing methods regarding water blocking substances inside the cable conductors. Because water blocking substances in the joint cause substantial thermal resistance and abnormal conditions and faults, the joint process is controlled to eliminate all problematic causes. Even though the conductor preparation and reassembling are especially difficult in rough working environments such as manholes, and the level of finishing and reliability are diverse depending on the proficiency of workers, this study expects that there is a point, wherein, both the recommended processing level of substance removal and the connection-thermal properties are simultaneously satisfied. Experimental results are conducted for types of the connection procedures, connectors, and testing current cycles. On stranded common aluminum cable connections, the suggested process ensures the thermal characteristics; nevertheless, the water blocking material is not completely removed as long as the procedure can maintain over 80% of the contact strands.

BAF57/SMARCE1 Interacting with Splicing Factor SRSF1 Regulates Mechanical Stress-Induced Alternative Splicing of Cyclin D1.

Background: Cyclin D1 regulates cyclin-dependent protein kinase activity of the cell cycle, and cyclin D1 alternative splicing generates a cyclin D1b isoform, acting as a mediator of aberrant cellular proliferation. As alternative splicing processes are sensitive to mechanical stimuli, whether the alternative splicing of cyclin D1 is regulated by mechanical stress and what kinds of factors may act as the regulator of mechano-induced alternative splicing remain unknown. Methods: The alternative splicing of Cyclin D1 was examined using reverse transcription polymerase chain reaction (RT-PCR) in osteoblast cell lines and keratinocyte cells loaded by a cyclic stretch. The expression of splicing factors and switching defective/sucrose non-fermenting (SWI/SNF) complex subunits were detected in stretched cells using real-time quantitative PCR (RT-qPCR). The protein interaction was tested by co-immunoprecipitation assay (Co-IP). Results: Cyclin D1 expression decreased with its splice variant upregulated in stretched cells. Serine/arginine-rich splicing factor 1 (SRSF1) and SWI/SNF complex subunit Brahma-related gene-1-associated factor 57 (BAF57), also named SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily E member 1 (SMARCE1), could respond to mechanical stimuli. Overexpression and knockdown experiments indicated the BAF57/SMARCE1 is probably a critical factor regulating the alternative splicing of cyclin D1. Co-IP showed an interaction between BAF57/SMARCE1 and SRSF1, implying a possible underlying mechanism of the regulator role of BAF57/SMARCE1 in the splicing process of cyclin D1. Conclusions: The splicing factor SRSF1 and BAF57/SMARCE1 are possibly responsible for the mechanical stress-induced alternative splicing of cyclin D1.

Structured light scanning measurement method based on mechanical splicing

测量大尺寸零部件一般需要较大的测量范围，而高精密扫描传感器往往视野较小。为了解决该矛盾，提出了一种基于机械式拼接的结构光扫描测量方法，通过结构光扫描仪获取局部高精点云，并利用高精十字平移台实现数据拼接。分析了测量系统的组成和测量原理，提出了一种基于加权非线性优化的外参标定方法，求解出结构光扫描仪和十字平移台之间非实物坐标系的变换关系。在实验中验证了系统在300 mm的测量范围内球心距的均方根误差（root-mean-square error，RMSE）优于45 μm；同时对实物进行了测量，检验了测量系统的实用性。

Örme Kumaşların Patlama Mukavemeti Üzerine Düğümleme Metotlarının Analizi

The study was carried out as two parts. In the published previous part, the spliced yarn performances were investigated to reveal optimum splicing method in terms of fiber type and yarn count on the basis of splicing methods including air splicing, wet splicing and mechanical (twin) splicing by using pure and blended ring-spun yarns containing cotton, viscose, polyester, modal, and acrylic fibers at different yarn counts of Ne 20, Ne 30 and Ne 40. The study revealed that twin splicer was the best for cotton fiber and acrylic fiber, whereas it was the worst for regenerated cellulosic fibers. All splicer types can be used for polyester fiber, and the best splicer type was air splicer for fine yarns, on the contrary, it was twin splicer for coarse yarns. The current study which is the second part of the study aimes to determine the bursting strength properties of the knitted fabrics on the basis of splice types. For this, the obtained yarns by splicing in different splicer in the previous work were knitted, and then the tests of structural properties and bursting strength were applied for the fabric samples. The results of the study unexpectedly indicate that splice types do not have effect on the bursting strength of the knitted fabrics in spite of the results of the previous study showing splice types clearly affect yarn strength. But, fiber types are effective on the bursting strength as expected. Besides, fabric structural properties do not have effect on the bursting strength because of constant knitting parameters.

Nonlinear finite element analysis of mechanical connections splicing precast columns with stiffened laminated metal plates

ABSTRACT The authors suggested mechanical connections for splicing two precast columns in their previous study. The present study proposes an efficient method of improving the performance of these connections consisting of laminated plates with additional interior stiffeners (interior bolts and rib stiffeners) to improve the efficiency of the design. The aim of this study was to develop a method for splicing two precast components using a pair of stiffened column plates with high-strength bolts, interior bolts and rib stiffeners, exploring the influence of the stiffened plates on the flexural capacity and the structural behavior of the mechanical connections. A non-linear finite element model was proposed considering damaged concrete plasticity, dilatancy accounting for the inelastic strains of the concrete materials, damage variables and plasticity and the concrete constitutive relationships, providing an efficient and dependable alternative to full-scale experimental investigations. This numerical investigation verified that the interior bolts and rib stiffeners contributed to developing optimized connections, enhancing the flexural resisting capacity of the spliced columns to almost the level of conventional monolithic cast-in-place columns. The abstract images illustrate the reduced deformation of the stiffened mechanical plates with the interior bolts obtained by the nonlinear finite element analysis.

Use of an international experience of mechanical reinforcement bars splicing in Ukraine

The problematic of reinforcement bars splicing by overlap tying and by the way of welding is described, as well as alternative splicing by the mechanical compression couplers as a way of its solution. Lap splicing showed good results in structures with small nominal dimensions of steel bars, low rate yield strength and in buildings not higher than 15 floors. Welding is the more flexible method of steel bars splicing but its use brings to rising costs and complicity of construction work. The quality of welded splices depends on many factors mainly on the existing problems in welding process. The analysis of world construction practice shows a more reliable, technological and effective way of splicing reinforcement bars it means the use of connecting couplers i.e. mechanical rebar coupling. Successful international experience of applying mechanical steel bars splicing in USA, Japan, China, Kazakhstan, UAE, etc. is described. It must be noted that with the advance of the enactment of DBN V 2.6-98 and DSTU B V.2.6-156, standard acceptable methods of steel bars splicing in Ukraine are lap splicing, welded connections and mechanical splicing. General technical requirements of the connections of reinforcement were analyzed and systematized, as well as general advantages of mechanical splices were proved. Analysis of international and native regulations showed that in Ukraine it should be taken more strict requirements for mechanical splices. Methodology and test results of mechanical splices were covered. A number of regulation documents were developed as a result of large scale theoretical and experimental research of mechanical connections. The technology of coupling of reinforcement bars was applied at many construction projects as well as in seismic regions.

Use of an international experience of mechanical reinforcement bars splicing in Ukraine

The problematic of reinforcement bars splicing by overlap tying and by the way of welding is described, as well as alternative splicing by the mechanical compression couplers as a way of its solution. Lap splicing showed good results in structures with small nominal dimensions of steel bars, low rate yield strength and in buildings not higher than 15 floors. Welding is the more flexible method of steel bars splicing but its use brings to rising costs and complicity of construction work. The quality of welded splices depends on many factors mainly on the existing problems in welding process. The analysis of world construction practice shows a more reliable, technological and effective way of splicing reinforcement bars it means the use of connecting couplers i.e. mechanical rebar coupling. Successful international experience of applying mechanical steel bars splicing in USA, Japan, China, Kazakhstan, UAE, etc. is described. It must be noted that with the advance of the enactment of DBN V 2.6-98 and DSTU B V.2.6-156, standard acceptable methods of steel bars splicing in Ukraine are lap splicing, welded connections and mechanical splicing. General technical requirements of the connections of reinforcement were analyzed and systematized, as well as general advantages of mechanical splices were proved. Analysis of international and native regulations showed that in Ukraine it should be taken more strict requirements for mechanical splices. Methodology and test results of mechanical splices were covered. A number of regulation documents were developed as a result of large scale theoretical and experimental research of mechanical connections. The technology of coupling of reinforcement bars was applied at many construction projects as well as in seismic regions.

Reversible Mechanical Regulation and Splicing Ability of Alginate-Based Gel Based on Photo-Responsiveness of Molecular-Level Conformation.

In this study, benefiting from the sensitive molecular conformation transversion in azobenzene, a new strategy for fabricating alginate gels with the abilities of splicing and photo-responsive mechanical adjustment is reported. Firstly, a 4,4’-azobis(benzoylhydrazide) (Azo-hydrazide) linker was used to crosslink alginate physically via the electrostatic interaction between hydrazide groups and carboxyl groups. It was then shaped and transferred in situ to a chemically crosslinked gel via 450 nm light irradiation. Under the irradiation, the molecular conformation change of azobenzene in the linker was able to form covalent bonds at the crosslinking points of the gels. Furthermore, the reversible conformation transformation of azobenzene was able to induce the increase and decrease of the storage modulus under irradiation with 365 nm light and 450 nm light, respectively, while also providing gel-like mechanical properties, depending upon the irradiation time and given wavelength. Meanwhile, the results also indicated that active groups could contribute to the splicing ability of the gel and construct a hollow cavity structure. It is believed that this work could provide a versatile strategy for preparing photo-responsive gels with reversibly tunable mechanical properties.

A RESEARCH ON DETERMINING OPTIMUM SPLICING METHOD IN TERMS OF FIBER TYPES AND YARN COUNT

The quality of the splice made in the yarn is very important in terms of final yarn performance. The yarn ends are not spliced well; the yarn breaking strength and elongation are reduced, resulting in too many breaks in the machines during fabric production and consequently low yield. Many methods, which are pneumatic method, the mechanical method, the pneu-mechanical method and electrostatic method, are used for splicing. Among them, pneumatic splicing is the most popular. In this study, it was aimed to investigate spliced yarn performances in terms of three types of splicing methods including air splicing, wet splicing and mechanical splicing known as twin splicing, and to reveal optimum splicing method in terms of fiber type and yarn count. For this aim, a total of twenty seven ring yarns as pure and blended containing different raw materials, which are cotton, viscose, polyester, modal and acrylic, were produced with different yarn counts having Ne 20, Ne 30 and Ne 40. The obtained yarn samples were spliced in different splicers including air splicer, wet splicer, and twin splicer on Savio Polar IDLS winding machine. The strength and elongation values of spliced yarns were measured with Mesdan-Lab Splice Scanner-3. The measurements were compared to each other and the values before splicing. The study results revealed that twin splicer is the best for cotton fiber and acrylic fiber, whereas it is the worst for regenerated cellulosic fibers, all splicer types can be used for polyester fiber, and the best splicer type is air splicer for fine yarns whereas it is twin splicer for coarse yarns.

Experimental evaluation of coupler behavior for mechanical rebar splices in reinforced concrete structures

Abstract The use of mechanical splices to connect steel bars is an important solution in many infrastructure projects worldwide. In Brazil, this system is rarely used. The Brazilian standards regarding this subject are old and out of date; particularly with regard to the performance evaluation test methods for these splices in the laboratory. This paper presents and discusses the test procedure proposed in the international standard ISO 15835 [1] in light of the current procedure defined by Brazilian Standard ABNT NBR 8548 [2], applied to types of mechanical splices commonly used in Brazil: taper threaded and bolted couplers. Performance parameters for these mechanical splicing systems related to structural integrity in reinforced concrete structures are evaluated on the basis of the results obtained in these tests. In the end, it is intended that this paper provide support for discussion of design procedures and laboratory performance evaluation of couplers for mechanical splices of steel bars in reinforced concrete structures in future reviews of Brazilian standard ABNT NBR 8548 [2].

Inelastic cyclic behaviour of RC members incorporating threaded reinforcement couplers

This paper describes an experimental investigation into the inelastic cyclic performance of reinforced concrete members incorporating mechanical reinforcement splices. Based on a survey of available mechanical splicing forms, two types of threaded couplers with different geometric configurations, namely ‘parallel threaded couplers’ and ‘parallel threaded sleeve couplers’ are selected for detailed experimental assessment. The fundamental uniaxial monotonic and cyclic response of reinforcement bars connected with threaded mechanical splices is firstly examined through bare (in-air) and embedded (in-concrete) tests, and their response is compared with that of their non-spliced counterparts. This is followed by an experimental study on four large scale reinforced concrete specimens subjected to lateral inelastic cyclic displacements, which provides a direct comparison between the performance of members with or without the two types of reinforcement couplers as well with or without a co-existing axial load. The test results enable a direct comparative assessment of the key response characteristics of the specimens including stiffness, strength, ductility and energy dissipation. Overall, the results show that members incorporating reinforcement bars connected through threaded mechanical couplers can provide considerable ductility and energy dissipation. However, the coupler-concrete interaction behaviour, which depends primarily on the geometry and location of the threaded coupler, has a significant influence on the inelastic cyclic response and ductility levels exhibited by reinforced concrete members. The experimental results indicate that the presence of the slender coupler alters the plastic hinge behaviour by localising the curvatures between the coupler and interface, reducing the rotational capacity. In contrast, the response of members with compact couplers, and without axial load, is virtually identical to that of the specimen with continuous reinforcement. The axial load enhances the stiffness and lateral capacity yet reduces the ductility performance due to a response strongly characterised by crushing. It is shown that whilst uniaxial in-air reinforcement performance may be adopted as a basis for selecting suitable mechanical couplers for use in dissipative members, the expected levels of ductility implied in current codified seismic procedures need to be carefully and explicitly evaluated when relatively non-compact couplers are employed.

Mechanical splicing of superelastic Cu–Al–Mn alloy bars with headed ends

This paper examines the feasibility of mechanical splicing using a steel coupler to connect headed ends of superelastic Cu–Al–Mn alloy (Camalloy) bars and steel reinforcing bars to be used in concrete structures. Although threading of Camalloy is as easy as that of steel, mechanical splicing using threaded ends requires machining of Camalloy bars into dog-bone shape to avoid brittle fracture at the threaded ends. The machining process requires significant time and cost and wastes substantial amount of the material. This paper attempts to resolve this issue by applying mechanical splicing using steel couplers to connect headed ends of Camalloy and steel reinforcing bars. To study its feasibility, we prepare 3 specimens wherein both ends of each Camalloy bar (13 mm diameter and 300 mm length) are connected to steel reinforcing bars. The specimens are tested under monotonic, single-cycle, and full-cycle tension loading conditions. From these tests, we observed (1) excellent superelasticity with recoverable strain of around 6% and (2) large ductility with fracture strain of over 19%. It should be emphasized here that, in all the specimens, ductile fracture occurred at the locations apart from the headed ends. This is in sharp contrast with brittle fracture of headed superelastic Ni–Ti SMA bars, most of which took place around the headed ends. From the results of the microstructural analysis, we identified the following reasons for avoiding brittle fracture at the headed ends: (1) Precipitation hardening increases the strength around the boundary between the straight and headed (tapered) portions, where stress concentration takes place. (2) The strength of the straight portion does not increase significantly up to the ductile fracture if its grain orientation is close to 〈0 0 1〉.

高密度模块化TDI CCD成像系统设计

In order to improve the high density assembly technology of remote sensing camera, a high density TDI CCD imaging system was designed with multichip module technology. First, TDI CCD focal plane with mechanical splicing technology was made to a copied unit. Then, the output energy of CCD output image signals was improved by a transistor emitter follower, they were transmitted to the analog front-end chips. Then they were converted into the 14 bits digital signals. After that they were integrated and processed through field programmable gate array (FPGA). In the end, through TLK2711 high-speed chip they were sent to data acquisition card on the computer. All the driving signals and processing signals of the imaging system were produced by the FPGA. The computer can control the imaging system and exchange the parameter through RS422 communication bus. The experimental results show that the area of driving layout cut down 2/3 than convention design. It realized the camera's high density assembly adopting the design of the mechanical and electrical integration of heat. And the total data speed can reach 3.6 Gbps in this imaging system, SNR can reach 52.6 dB.

Toward High-Power All-Fiber 2–5 μm Supercontinuum Generation in Chalcogenide Step-Index Fiber

In this paper, a high-power spectrally flat 2-5 μm supercontinuum (SC) laser is reported in a piece of As2S3 chalcogenide step-index fiber. A fluoride fiber-based SC laser which spans from 2-4.2 μm is used as the pump light. Two pump coupling systems between the fluoride and As2S3 fibers, one based on aspheric lens coupling and the other using all-fiber mechanical splicing are investigated. With the setup of aspheric lens coupling, the obtained SC laser has a 10 dB spectral bandwidth of 3000 nm spanning from 2050 to 5050 nm, corresponding to an average power of 57.6 mW. While with the all-fiber mechanical splicing, the 10 dB spectral bandwidth of the SC laser shrinks slightly, spanning from 2140 to 4980 nm range, but the average output power is further scaled to a record power of 97.1 mW. It is found that the dominant nonlinearities for continuous spectral broadenings in the As2 S3 fiber are self-phase modulation and stimulated Raman scattering in the normal dispersion regime. This paper presents an all-fiber mid-infrared SC laser with spectrum beyond 5 μm for the first time. It also offers a practical solution for robust and reliable high power 2-5 μm broadband fiber laser.

Pembangunan Aplikasi Penyambungan Kabel Fiber Optic Menggunakan Metode Fusion Berbasis Simulasi

Splicing of optical fibers have two methods i.e fusion splicing and mechanical splicing. Fusion splicing method is chosen because this method is gives permanent fusion. Fusion splicing is the act of combining two optical fiber end-to-end using heat parallel electrodes. The goal is to combine the two fibers together such that light passing through the fiber scattered or reflected back. Merging optical fiber using this method to connect Fusion Splicing can be done using a tool arc fusion splicer. Arc fusion splicer is a tool that is used to connect the optical fiber using parallel electrode rod smelting technology for accurate light reflection perfect. This study is to build simulation about how to splicing optical fibers using fusion splicing. Simulation program is chosen because of the price arc fusion splicer is very expensive ranging from millions rupiah in 2014, so this simulation media may be one visualization of the original tools of arc fusion splicer. The expected goal is to be able to know how to connect the fiber optic cable is good and right fiber optic cable by using simulation based on Internatonal standards ITU-T ( International Telecommunication Union ) . Keywords: Fiber Optic, Fusion Splicing, Mechanical Splicing, Arc Fusion Splicer

BARRIERS TO NEW TECHNOLOGY DISSEMINATION IN THE CONSTRUCTION INDUSTRY

Despite the common belief, there is a considerable amount of innovation that occurs in the construction industry. However, the construction industry has been relatively slow to embrace the full potential of many new technologies. Evidence suggests that there is a lag in the uptake and effective implementation of several new technologies such as mechanical rebar splicing system. The objective of this study is to identify the impediments or barriers to the implementation of innovative technologies such as mechanical rebar splicing systems in the construction industry. A comprehensive literature review is conducted to identify and classify the barriers to new technologies dissemination. The findings of this literature review are validated using interviews with the construction industry experts. This study contributes to the state of knowledge by identifying and classifying the barriers that generally hinder the dissemination of new technologies in the construction industry. The practitioners can utilize the findings of this study to design appropriate strategies to overcome the barriers for implementation of new construction technologies. As part of this study, the extent to which the identified barriers have hindered the adoption of rebar splices, a technology that has not been adapted to its full potential. A questionnaire was designed, which was categorized the identified barrier in five major categories of cost, society and regulation, knowledge, marketing, and technical matters. The findings of the survey it was concluded that the lack of knowledge has the highest level of impact.

Investigations and Non-destructive Testing in New Building Design

Mechanical rebar couplers are preferable in the advanced building construction and structural design of antiseismic elements. The paper presents destructive inspection techniques used to investigate stress fields (tensile and compressive) and deformation curves for mechanical rebar splicing. The properties of mechanical rebar splicing are investigated by the non-destructive testing digital radiography. The behavior of real connections (column-to- column, beam-to-column) is studied under static and dynamic loads. Investigation results allow the elaboration of recommendations on their application in the universal prefabricated antiseismic structural system developed at Tomsk State University of Architecture and Building, Tomsk, Russia.