Search

This work presents a review of the current state-of-the-art in composite joints, which are commonly considered one of the most promising techniques emerging in the past few decades. The paper thus assesses existing work on composite joints for various connections, with a focus on the effects of their interaction. The investigation included experimental studies, numerical studies, design code literature reviews, cyclic loading studies, seismic studies, and monotonic load studies on composite joints, along with an examination of recent papers investigating beam-column connections. This work thus summarises the extant literature on composite joints for various connections to outline the resulting knowledge gaps and to offer possible research directions on composite joints that might enable a greater understanding of such joints to be developed. [ABSTRACT FROM AUTHOR]

The paper deals with the issues of studying deformation properties and creep of sulfur-containing wood concrete composites exposed to permanent loads and various compressive stresses. The study of these aspects is of great interest for the foreign researchers from neighboring countries and abroad, especially in the regions with extreme continental climate. Sulfur-containing wood concrete composites are the most lightweight building materials with lower heat conductivity and enhanced sound insulating properties. Modern theory and practice of creation and development of technologies for wood concrete wall blocks on the base of composite sulfur-containing binders served as the methodological framework of the research. Standard measuring instruments and analysis methods of chemical, physical and mechanical properties were used when implementing experiments. In all the experiments, the samples were lightweight concrete prisms with the cross section 150x150mm and the length of 600mm. One batch of the samples was made from sulfur-containing wood concrete, with crushed reed fiber being the organic component, while the second batch was prepared from sulfur-containing expanded clay concrete for comparison purposes. The samples were exposed to permanent loading by means of specially prepared spring specimens. As the research results shown, the rate of creep growth for sulfur-containing lightweight concretes depends on the curve of strength increment in time demonstrating the concrete hardening process. Thus, if compared with sulfur-containing lightweight concretes, creep of sulfur-containing wood concrete is significantly lower that leads to creep reduction at the same level. The results of the investigation could be applied at manufacturing of effective wall materials for residential construction, in particular in seismic areas. [ABSTRACT FROM AUTHOR]

The reason of the research was insufficient knowledge among professionals (architects and construction workers) about the composite materials in general, and about Fibre Reinforced Polymers (FRP) in particular. In the authors' opinion, such a situation results from a poor education in FRP (which was also reported by the Architects Council of Europe), as well as lack of FRP-oriented vocational trainings: IVET (Initial Vocational Education and Training) and CVET (Continuing Vocational Education and Training). The paper presents the specific of the Polish construction market in terms of FRP applications, level of knowledge and practical skills among professional users (architects, civil engineers and construction workers at each stage of the whole construction process of composite designing and applications). The analysis presented in the paper are based on the authors' own investigations, as well as the development of the statistical data. [ABSTRACT FROM AUTHOR]

The paper considers the issue of designing high-strength concrete for producing concrete blocks for Lego-technologies. Lego-technology is the development of groove-and-cog systems of positioning and connecting small-piece wall elements. The possibility of obtaining hollow-core thin-walled Lego-blocks on the basis of self-compacting high-strength fine-aggregate concretes with various types of high-porous filling has been considered. The paper suggests compositions of high-strength concrete mixes for manufacturing Lego-blocks frames. The special attention at designing was paid to improving producibility of their manufacturing and the maximum efficiency of clinker component usage. Due to the difficulty of using conventional fiber reinforcement in this concept, the application of specially designed admixtures, micro-reinforcing the composition at cement stone level, was suggested, which has increased the compressive strength up to 20...25%. [ABSTRACT FROM AUTHOR]

The composite beam is a structural component that made by two or more independent elements that are joined or connected together to form a structural unit. The composite beam consists of steel-wood, wood-concrete or with composite composites. A checkered steel plate also known as a reticulated steel plate, is a metal plate with a convex or concave pattern on top. Fiber reinforced polymer composite beams usually consist of carbon, glass, aramid, basalt and other fibers such as paper, wood, or asbestos. The checkered steel encased beam usually consists of U-shaped or C-shaped form. Aramid fiber is a man-made polymer that is produced by spinning solid fiber from a mixture of liquid chemicals. The fibres have good impact resistance, and low modulus grade are widely used in ballistic systems. The primary advantages are better resistance towards chemical activities, improved fire resistance. It is also found that they have better physical qualities than glass fibres. In this parametric study, different angles of checkered steel encased beams including 90°, 80°, 70°, and 60° is considered and analyzed by the experimental process. The numerical comparative study including checkered steel-encased beams with aramid fiber reinforced polymer encased concrete (AFRP) using ANSYS software are discussed depending on the various critical reviews available for the studies. [ABSTRACT FROM AUTHOR]

The paper presents the results of studies of the influence of the degree of mutual solubility of metals and alloys in obtaining composite materials with a metal matrix on the organization of the structure. The studies show that for materials with different degrees of mutual solubility of components the organization of the structure differs significantly, which must be taken into account when making products with composite structure. Samples based on components with limited mutual solubility are most susceptible to cracking, especially with excessive formation of intermetallic phases. When obtaining composite materials based on alloys, formation of secondary phases is possible not between the main components, but between the alloying elements. The melting temperature and density of the components, which additionally determine the structure organization of the samples, also have a significant influence when obtaining composites. [ABSTRACT FROM AUTHOR]

Composite steel-concrete beams have been shown to have superior structural properties in terms of stiffness and strength after compared to reinforced concrete or steel beams alone. Nonetheless, most steel beams are currently completely attached to the concrete slab, indicating that the connectors are welded through the steel decking on to the steel beam and casting into the concrete slab to provide the necessary shear connection, but the composite behavior differs significantly in fire than in normal conditions. This paper focuses on a review of recent studies that revolve around the structural behavior of composite beam systems and their behavior in fire events through numerical and experimental studies in order to address the efficiency and applicability of composite beams. [ABSTRACT FROM AUTHOR]

This paper studies the flexural experimental behavior of an asymmetric castellated composite beam with an encased steel web by RPC (reactive powder concrete) casting in a steel web beam as a composite member with and without lacing rebar effect. The cross section made from steel beam and concrete deck slab. The steel beam (asymmetric section) made from two parts of the Tee section; the top part cut from IPE 180 (steel beam) and the bottom part is cut from IPE 200 (steel beam). Use RPC (reactive powder concrete) to strengthen the steel web. From the results, the difference in ultimate service load capacity equals (+10.51% and 19.14%) with reactive powder concrete and reactive powder concrete with lacing effect respectively. [ABSTRACT FROM AUTHOR]

This paper studies the flexural experimental behavior of an asymmetric castellated composite beam with an encased steel web by RPC (reactive powder concrete) with and without lacing rebar effect using a gap between the two parts of the steel web. The cross section made from steel beams and concrete deck slabs. The steel beam (asymmetric section) made from two parts of the tee section; the top part cut is from IPE 180 and the bottom part cut from IPE 200. The RPC was used to connect the steel web without welding. From the results, the difference in ultimate service load capacity using gaps (0%, 10%, and 20%) from web depth equals (+8.36%) with a gap of (20%) from total depth, a decrease equal to (-18.59%) with a gap equal to 0% gap, and a decrease equal to (-2.96%) with a gap equal to 10% gap. [ABSTRACT FROM AUTHOR]

In Finite Element analysis the size of mesh plays a critical role. It is closely said that accuracy and number of mesh required for the meshing of the element. This paper presents the effect of the von misses and various constraints on the accuracy of the result. On the basis of the papers referred and guidelines obtained for choosing the appropriate mesh size in finite element analysis has been provided and explained about the von misses stress occurred in the model. The web reinforcement should be strengthened enough to carry tension forces as well as compression forces so that the compression wrinkling is avoided. Von mises proves to be the perfect safe value for the designing of composite structures which involves various stress theories and failure criteria. [ABSTRACT FROM AUTHOR]

In this paper, the work basically deals with the modeling and analysis of the propeller blade of aircraft for its strength. A propeller blade is complex 3D model geometry. This requires high end modeling CAD software is used for generating the blade model in CATIA V5 R20. This paper consists of brief details about Fiber Reinforced Plastic materials and the advantages of using composite propeller over the conventional metallic propeller blade. This paper focus on the metal and composite strength analysis of the propeller blade carried out by using the finite element analysis. By using ANSYS software static, modal were carried out for isotropic material. In this work two different types of propeller i.e. Aluminum, Composite, were studied using FEA techniques. [ABSTRACT FROM AUTHOR]

This paper presents the results of the research stage focused on applications of composite materials in aviation, carried on by an international team of European Project Semester students at the National Institute for Aerospace Research "Elie Carafoli" – INCAS, as Research Partner of the University POLTEHNICA of Bucharest, as Organizer and EUROPEAN PROJECT SEMESTER Provider. The study case is a light aircraft wheel cover. The objectives are set to the determination of the body geometry by reverse engineering techniques, modeling and numerical simulations for aerodynamics and structural analysis. A scale reduced demonstrator was obtained through 3D printing. [ABSTRACT FROM AUTHOR]

The most popular flooring solution for composite building construction is composite slabs, which are made of profiled steel sheets and a concrete topping. The elimination of traditional replaceable shuttering and the need for as many props are thought to be the main advantages of this structural system, along with faster construction. This paper presented an overview of composite slab systems, and illustrate the significant of composite slab systems. A comprehensive literature review on the topic is given. The use and application of composite slab systems is presented. Significant factors such as deflection, slippage, fatigue, shear-bond, cost effective and construction recommendations were discussed. Advantages and disadvantages in using composite slab systems are stated and analyzed. Some considerations and future research direction were drawn. [ABSTRACT FROM AUTHOR]

The fibre-reinforced composite structural members play an essential role in enhancing the strength-to-weight ratio of the structure. Smart reinforcing fibres like Shape Memory Alloy (SMA) provide an additional feature of adaptive stiffness to the structure. In this paper, SMA wire-reinforced epoxy resin composite is analyzed for change in natural frequency with respect to change in transformation temperature of SMA wires to reveal the difference in stiffness of composite beam, which is a function of change in transformation temperature from martensite to the austenite phase. The numerical study is carried out using FEA software, and the experimental validation of the same is completed. The natural frequency shift is predicted by measuring the natural frequencies of the composite for free-free boundary conditions at different transformation temperatures. The significant change in the natural frequency of composite is observed during the shift in transformation temperature, and the FEA results are close to experimental results with reasonable accuracy; thus, the proposed composite provides adaptive stiffness. [ABSTRACT FROM AUTHOR]

Functionally Graded Materials (FGMs) are new composite materials that are modified to combine two or more materials with gradations to build the required material properties. The properties of FGMs used in this paper are metal and ceramic. Metal is resistant to structural flexibility, while ceramic is a material that is resistant to high temperatures. This paper presents the free vibration of FGMs using the Discrete Shear Beam (DSB) Element. Numerical results for a simply supported beam with L/h =20 are evaluated. The results are then compared to the reference solution from the literature. From the analysis, the DSB element gibes good results for all beams problems evaluated in this paper. [ABSTRACT FROM AUTHOR]

This paper presents comparison of analytical and experimental result discussion for vibration analysis of composite beam with crack. Beams and beam like elements are principal constituents of many mechanical structures and used widely in high speed machinery, aircraft and light weight structures. Finite Element Analysis is performed using ANSYS 14.5. The model of beam is generated and used for Finite Element Analysis. The modal analysis is used to determine the natural frequencies and mode shapes of a structure. The experimental analysis is carried out by using a Fast Fourier Transform (FFT) device which is used to detect the potential faults and checking the condition of the machine through the vibration analysis. Accelerometers often come with a calibration certificate stating the exact reference sensitivity. [ABSTRACT FROM AUTHOR]

Cracks in engineering structures affect the dynamic characteristics and leads to failure of beam structures over a period of time. The crack will propagate due to vibration characteristics and the resultant fatigue in the beam structures. This paper focuses on a cantilever beam subjected cracks of different depth and its location under free vibration. The effect of such vibrations and crack are analyzed. Different aluminium alloys which find modern application in areas like aerospace, automobile, marine, construction industry etc. are considered for analysis. The change in modal shape and natural frequency of the beam structure due to crack under free vibration analysis is carried out by changing the crack location, crack depth and also the material properties by Finite Element Method (FEM) using ANSYS software. The natural frequency of the beams under test comprising of different Aluminium alloys is compared for various location and depth of crack. The modal shape of the free vibration analysis of the Aluminium alloy beam shows that the crack brings down the natural frequency level and it gets further reduced when the crack depth increases. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate the behavior of shear composite girders (flat & zigzag webs). The experimental work involves testing six composite girders to investigate the influence of web height and the effect of using a zigzag web under shear loading. Three web heights (400, 600, and 800 mm) were considered for all specimens. The steel girders were 1800 mm overall length, and the composite concrete slab were 460 mm, and150 mm width and depth, respectively. The resulted are showing in from where of a recorded load of capacity, mid-span deflection, and crack pattern for the girders of composite, and the slip between the deck of concrete and steel girder. Increasing the web height resulted in reduce the vertical deflection, slip, and the cracks were limited at the loading zone. The curves of the load-displacement and stress distribution predicted by the FEM agree well with those obtained from experiments, proving the accuracy of the suggested FEM. [ABSTRACT FROM AUTHOR]

A composite beam-to-column joint formed by a composite concrete slab and two cold-formed steel C-sections placed back-to-back as beam and column had been investigated experimentally. The experimental results are presented in this paper. Three specimens with cruciform subassemblies of cold-formed steel (CFS) beam-to-column joint and three push-out samples were tested with a novel approach to different shear connections: nut bolt, cold-formed angle, and cold-formed corrugated plate. The joints were made from CFS with an 8 mm thickness and were built using only angles from the top and seat. The results show that using a cold-formed steel corrugated plate results in a rotation capacity of 25.2 mrad, which is close to the semi-rigid connection rotation capacity limit (30 mrad). Although only the bar minimum of reinforcement is used, these joints will become semi-rigid as the proportion of steel reinforcement increases. This is extremely helpful in plastic design in composite structures. Small slips are also visible in composite joints and push-out specimens for all types of shear connections. The push-out results show that the specimen bolt shear connector has approximately 52.7 percent more strength than the specimens with angle plate and corrugated plate shear connectors. As a result, the shear connection type and degree significantly impact the composite beam-to-column connection's behavior and rotation ability. [ABSTRACT FROM AUTHOR]

Composite material combines two or more materials into one combined material to get the desired characteristics of each material. Functionally Graded Material (FGM) is a type of composite material that combines two materials in the form of gradation of materials that is being developed as an alternative to the conventional composite material. To support this material, numerical simulation by the Finite Element Method (FEM) is very interesting. In this paper, the Discrete Shear Beam Element (DSB) element is used to evaluate the effect of the shear correction factor in FGM beam structures. In much of the literature, the shear correction factor is assumed to be constant. This assumption is correct for isotropic structures, but in FGM structures, this factor is not constant. A simply supported beam with various boundary conditions and thickness length ratio is evaluated to understand the effect of this factor. The results show that by using the true shear correction factor, the results will be close to the reference solution. Moreover, for the FGM beam with the significant ratio of modulus elasticity, the use of the true shear correction factor is a must to get a solution as close as possible to the reference solution. [ABSTRACT FROM AUTHOR]

This paper studies the flexural experimental behavior of an asymmetric castellated composite beam with an encased steel web by RPC (reactive powder concrete) casting in a steel web beam as a composite member with and without lacing rebar under the effect of repeated loads. The cross-section is made from steel beams and concrete deck slabs. The steel beam (asymmetric section) is made from two parts of the tee section; the top part was cut from IPE 180, and the bottom was cut from IPE 200. Use RPC to strengthen the steel web with and without rebar lacing. The results show the difference in ultimate service load capacity by (+14.56) with RPC without rebar lacing and (+23.84) with RPC with rebar lacing under repeated loads. [ABSTRACT FROM AUTHOR]

The growth of population density and shortage of land in urban area are two major problems for all developing countries including India. In order to mitigate these two problems, the designers resort to high-rise buildings, which are rapidly increasing in number, with various architectural configurations and ingenious use of structural materials. Consequently, in this paper, an alternate methodology is adjusted via doing, a relative investigation of two structures with 25 story wherein. i) The shear dividers are not associated by coupling beams. ii) The shear dividers are associated with steel composite coupling beam. To break down the over two cases ETABS 2018 programming was utilized. Further boundaries like variety in displacement, story drift, time period, frequency and base shear of the structures are thought to make examination between the two cases. Results have shown that interfacing the shear divider by steel composite coupling beams can adequately decrease the seismic tremor incited reactions. By giving the steel composite coupling beam in the middle of the shear divider, gave preferable outcomes over the, structure put without coupling beam in the middle of shear divider. [ABSTRACT FROM AUTHOR]

The current paper presents the results of an experimental study conducted on flexural behaviour of steel-concrete composite beams, each beam consisting of rectangular Reinforced Concrete (RC) section encased with a steel I-section. A new type of composite beam prepared with GFRP reinforced concrete encased with steel section was proposed and studied which can provide better corrosion resistance. A total of six beams, of uniform size 150 mm wide, 200 mm deep and 1000 mm long, were cast and tested under four-point bending. Of six beams cast, three beams were reinforced with GFRP rebars and the remaining three beams were reinforced with steel rebars. Three different grades of concrete were used for casting. The behaviour of steel-concrete composite beams reinforced with steel and GFRP rebars were observed. The observation made were load versus mid-span deflection, concrete strain, strain of steel I-beam. The test result indicates that using encased steel sections can provide a significant improvement in load carrying capacity and stiffness of RC beams. [ABSTRACT FROM AUTHOR]

In this paper, the reference sample of Magnesium oxychloride cement (MOC) and a MOC-based composite with graphene and Lunar regolith simulant were prepared and analyzed. Graphene was added to the prepared composite in order to increase the strength, while the Lunar regolith simulant was used as a filler. The regolith simulant was analyzed using X-ray diffraction, X-ray fluorescence, sorption analyzer, laser diffraction, scanning electron microscopy and energy dispersive spectroscopy. The composite and the reference sample were analyzed with X-ray diffraction, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. Moreover, the mechanical properties and porosity were also determined. Despite a significant decrease in the mechanical properties, such material can find application on the lunar surface. [ABSTRACT FROM AUTHOR]

In this paper, two metals of different mechanical properties were bonded and subjected to cyclic loading that produces variable, repeated and fluctuating stresses on the composite Beam. However, the fatigue and static loading were investigated and analyzed while taken into account the safety factor, life and number of cycles. In addition, having known the two materials ultimate tensile strength and endurance limit, each face sheet is analyzed in order to observe the stresses distribution on the layers. Finite element software ANSYS Workbench was used for the simulation and analysis of the composite beam. However, it is essential to understand the fatigue behavior of composite beam to avoid sudden ultimate failure, as it is the major cause of 90% mechanical failure, it tends to fail below yield strength. In general, it was observed that the top face sheet has the most stress and lower safety factor than the bottom sheet, thereby addition of materials with high endurance limit and ultimate tensile strength at the loading region will enhance the life of the composite beam, as well as the safety factor. [ABSTRACT FROM AUTHOR]

In this paper, the effect of face sheet thickness on the bending behavior of sandwich beams was investigated. The structure used for analyses was a composite sandwich beam with aluminium as skin and epoxy as core. Finite element analysis was carried out on the structure using ABAQUS software. To investigate the bending of the composite beam, three-point bending tests were performed on the material and mid-span deflections were recorded. Different results such as force vs deflection, mass, and Von Mises stress were obtained and analyzed by changing the thickness of core. Research findings revealed that the thickness of beam skin affected its mass and flexural stiffness. Moreover, as the thickness was increased, deflection was decreased if the same force was applied to the beam. As the thickness of the face was increased, beam mass was also increased. Finally, we observed that the beam with the highest thickness had the biggest Von Mises stress when the same deflection was required for different face thicknesses. [ABSTRACT FROM AUTHOR]

One of the reasons for the unsatisfactory results of using multidimensional analysis to determine composite quality indices of systems may be the specifics of the data used. Traditionally used as an initial transformation, data scaling does not eliminate the existing data properties. Logarithmic transformation is usually mentioned as possible, but recommendations for its use in the construction of composite indicators are not given. The paper proposes a criterion for the application of logarithmic transformation of variables. Logarithmic transformation is necessary exclusively for anomalous variables. An anomality criteria based on the signal-to-noise ratio of data in a proposed standard form is used. Visually abnormal variables can also be identified using heat maps. The proposed analytical method for detecting anomalous variables coincides with the results of heat map data analysis. The evaluation of the effectiveness of using logarithmic transformation in assessing the quality of poorly formalized systems is examined. Composite indexes of the quality of life for regions of the Russian Federation are calculated. The use of logarithmic correction for anomalous variables solves the problem with the negativity of the weighting coefficients as well as providing a more correct socio-economic interpretation. [ABSTRACT FROM AUTHOR]

Bio-composites are essential materials created from renewable resources that biodegrade and sustainable such as bamboo fiber to produce a new generation of composites for construction industry used. Even though most bamboo grows in forest, there is still a scarcity of data on the morphology, physical, chemical, and mechanical properties of cultivated wild bamboo in Malaysian forest. Hence, the aim of this research is to determine the physical, chemical, and mechanical properties of species Gigantochloa Scortechinii (Buluh Semantan) suitable criteria for bio-composite material. In this paper presents the research on Sample A and Sample B of Buluh Semantan species that was discover in Royal Belum State Park as the case study for gathering the sample. Several experimentations were conducted on bamboo fiber and bamboo culm by referring to ISO 22157 and TAPPI standard procedure. The outcome revealed that Sample B has better in mechanical strength due to the higher content of lignin, the greater the density also higher content of alpha-cellulose and holocellulose led to lower moisture content which led to suitability usage as bio-composite material. This finding will provide as a source for commercial purpose in analyzing the capabilities of Buluh Semantan as bio-composite materials in construction sector. [ABSTRACT FROM AUTHOR]

This research is focused on the load-bearing capacity and the number of coupling elements in steel-concrete composite beams. The influence of the change of the input parameters of the beam, with special focus on the dimensions and materials of the steel profile and the concrete slab, was investigated. Furthermore, it was found out how the load-bearing capacity and the number of coupling elements will be affected by the change in the height and thickness of the shank, and the material of the shear stud itself. The results of this paper should serve as the input data for the next step of the research, where we consider the replacement of shear studs with blind bolts and thus achieving demount ability of the structure at the end of its life. [ABSTRACT FROM AUTHOR]

In the present paper, nonlinear finite-element analyses (FEA) have been conducted for investigating the conduct of simply supported composite steel-concrete plate girder having web opening subjected to static loading. Five Steel Concrete Composite Plate Girder samples have been taken for the verification. One of such girders was regarded as a control girder, which possesses no web openings. Two girders have a square opening and contain a circular web opening, correspondingly. And, the other two girders have reinforced openings. ANSYS software (version 19.3) has been employed for analyzing the 3D model. Results of the present work were validated with an experimental work from the literature. The validation was achieved through the comparison of Load-Deflection curves, and the modes of failure were obtained from the finite element (FE) model with that of Experimental. These specimens were analyzed to validate their competence and effectiveness. The comparison between the Load-Deflection curves resulted from the FE model with those of investigational evinced a good agreement. The results manifested that the ratio of the numerical maximum load strength to the experimental maximum load strength for the first control girder 93%, when the composite girders containing square and circular openings in web the ratio 88% & 92% respectively. While for the composite strengthening openings girders the ratio were 89%, and 92% respectively. [ABSTRACT FROM AUTHOR]

Cold-formed steel (CFS) sections are well known due to its lightweight and high structural performance which is very popular for building construction. Conventionally, they are used as purlins and side rails in the building envelopes of the industrial buildings. Recent research development on cold-formed steel has shown that the usage is expanded to the use in composite construction. This paper presents the modelling of the proposed composite connection of beam-tocolumn connection where cold-formed steel of lipped steel section is positioned back-to-back to perform as beam. Reinforcement bars is used to perform the composite action anchoring to the column and part of it is embedded into a slab. The results of the finite element and numerical analysis has showed good agreement. The results show that the proposed composite connection contributes to significant increase to the moment capacity. [ABSTRACT FROM AUTHOR]

This paper study about the flexural theoretical behavior of Asymmetric castellated composite beam with encased steel web by RPC (reactive powder concrete) casting in steel web beam as composite member with and without lacing rebar effect by using gap between two part of steel web. The modeling and Finite Element Analysis was done using ABAQUS/2016. The cross section made from steel beam and concrete deck slab, steel beam (Asymmetric section) made from two part of Tee section, top part cut from IPE 180 and bottom part cut from IPE 200. Use RPC (reactive powder concrete) as strengthening at steel web and without welding of two part of steel web. From results increase ultimate load capacity by using gap (10% and 20%) from total depth equal to (3.39 and 11.25)respectively and decrease equal to (-19.87 %)with gap equal to zero. [ABSTRACT FROM AUTHOR]

This paper presents the results of numerical simulation of a synchronous infrared thermography process for non-destructive testing of a composite three-layer panel with a honeycomb core. Ansys 14.5 software product was used as a calculation tool. Using this software, the problem of non-stationary thermal conductivity was calculated by the finite element method. The problem was considered in three dimensional projections. Convective and radiant heat transfers with the environment were taken into mathematical model. Based on the numerical modeling results, the changes in temperature fields on the control object surface were obtained for calculation cases, which allowed assessing the possibility of detecting defects, as well as determining the time of defects occurrence during nondestructive testing by synchronous thermography method. [ABSTRACT FROM AUTHOR]

In the recent years, composite construction has gained its popularity due to achieving economy and providing higher sustainability compared to conventional steel structure or reinforced concrete structure. In various modern technologies, strengthened as well as sustainable materials are used in the present era for advanced infrastructure. This paper comes with a solution for several issues by introducing steel-concrete composite structure connected by shear connector. Strength of concrete is an important parameter for composite construction. In this paper, an attempt has been made to review the response of changing concrete property in composite beams. Constituent materials, their types and strength of concrete are the main parameters taken for this current paper. Concrete is highly efficient in compression whereas steel in tension. Thus with the use of these two materials, structure will become highly efficient in tension as well as compression. Steel concrete composite structure can be used in many applications in practical field but usually bridges and multistoried commercial buildings are the most used type of composite structure due to high load carrying capacity and reduced cost of maintenance. [ABSTRACT FROM AUTHOR]

The paper proposed a model of surface modification of a titanium billet by electron beam treatment with using synthesized modifying powders of the Ti-Al-C system. The model takes into account change in the phase composition, heat loss by radiation, melting and shrinking of the powder layer. The change in phase composition is modeled by a detailed reaction scheme. During the calculations it is determined the temperature and concentration fields of pure substances and chemical compounds, effective properties, porosity and layer thickness distributions at different time positions; thermal cycles at specified points of the specimen are analyzed. It is shown that in the result of the modification a heterogeneous multi-phase coating forms from powder layer containing titanium carbide and Max-phase. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the possibilities of applying the method of microfocus X-ray diffraction to assess microdamages in structures made of composite materials. We carried out a qualitative and quantitative assessment of microdamages arising during mechanical tests in the construction of polymer composite materials using the example of a structurally similar element of a flange having a L-shaped section and made of carbon fiber using the technology of autoclaved molding. During the experiment, radiographic images of the sample were obtained at fixed levels of tensile force. The obtained images were analyzed for the appearance of interlayer separation as the main type of damage arising in the microstructure of the analyzed detail. We determined the locations and approximate values of interlayer cracks sizes at various load levels. We found, that after removal of the load, interlayer cracks “close” and are hardly identified by means of non-destructive testing afterwards. [ABSTRACT FROM AUTHOR]

The paper presents free vibration of shape memory alloy hybrid composite beams by experimentally. The hybrid composite beams are fabricated using glass fiber with epoxy resin matrix implanted with the Ni-Ti SMA wires with diameter 0.47mm. The rectangular cross-section of beams with sizes, thickness, 3mm, width, 20mm and length 250mm are considered in the investigation. Free vibration test has been performed for the cantilever beams to investigate the effect on the fundamental natural frequency shift by changing the current as well as increasing the number of SMA wires. The fundamental natural frequency of the beam has shifted on higher side, 12.82% for single wire and 35.48% for two wires implant under the influence of current in comparison with no current state. Further, as supplied current increases in the SMA wire the natural frequency of beam increases helps in improving the stiffness and encourages to avoid resonance state. [ABSTRACT FROM AUTHOR]

Using the general theory of composite beams, we derived expressions for shear forces between cable elements. This study is the first to determine the forces of interaction between the armor and conductor of the submersible pump cable, which is considered as a composite beam with transverse bracing. The paper analyzes the forces of interaction of cable components and identifies the distribution pattern of the forces in the cable deformation zone. The findings can be used for designing submersible pump cables in the oil industry, taking into account high hydrostatic pressure and high temperatures. [ABSTRACT FROM AUTHOR]

In this paper, a method of mechanical impact on an element of a ring frame of a U-shaped cross-section with the aim of opening a closed delamination to a minimum size is considered, which will allow this defect to be detected by the nondestructive X-ray diffraction method, in condition that the loading will not lead to the formation of new defects and further growth of the existing ones. [ABSTRACT FROM AUTHOR]

Analysis of design methods for composite beams with curvilinear fiber trajectories is considered in this paper. The novelty of this approach is determined by the fact that traditional composite materials are typically formed using prepregs with rectilinear fibers only. The applications of the results are associated with designing shaped members with a composite structure by using of biomechanical principles [1,2]. One of the problems is evaluation of the effect of fiber misorientation on the stiffness and load carry capacity of a shaped composite element with curvilinear fiber trajectories. An equistrong beam with a constant cross-section area is considered as an example, and it can be produced by forming of a unidirectional fiber bunch impregnated by a polymer matrix. Methods for evaluating the effective elastic modulus for structures with curvilinear fiber trajectories are validated. The misorientation angle range (up to 5 degrees), when a material with required accuracy can be considered as homogeneous, is determined, fiber misorientation being neglected. It is shown that, for beams with a fairly small height-to-width ratio, it is possible to consider only 2D misorientation. [ABSTRACT FROM AUTHOR]

Composite beam construction usually associated with old-style Hot-Rolled Steel Section (HRSS) has proven to act much better in compare with Cold-Formed Steel Section (CFSS) sections due to thicker section. Due, it's getting popular to replace HRSS with CFSS in some aspects as a composite beam. The advantages such as lightweight, cost effective and easy to install have contributed to the apply CFSS as a preferred construction material for composite beam. There is a few technical data available regarding the application of the usage of CFSS as a composite system, despite the potentials use for residential and light-weight industrial constructions. This paper presents an experimental tests results which have been conducted using CFSS as composite beam. Composite action of CFSS arranged as double beam with Self-Compacting Concrete (SCC) slab are integrated together with bolted shear connectors were used. A full-scale test comprised of 3 proposed composite beam specimens with bolted shear connector spaced at 300 mm interval of grade 8.8 was using single nut with washer on flange of CFS, cast to the slab and loaded until failed. The test show that the bolted shear connector yielded better capacity of ultimate strength and ultimate moment for the proposed composite beam. It can be concluded that, bolted shear connectors of 16 mm in diameter performed better than the other diameter size of bolted shear connectors. [ABSTRACT FROM AUTHOR]

The energy-saving fired facing brick composite wall has a broad development prospects due to its merits of thermal insulation, energy conservation, beautiful, and natural. The construction and characteristics of this wall are introduced and analyzed in this paper. Experimental studies of samples are also conducted to investigate its compressive performance. The results show that the energy-saving fired facing brick composite wall has high compressive capacity. It has considerable application prospect, the study in this paper provides foundation to further studies. [ABSTRACT FROM AUTHOR]