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An experimental study was performed to investigate the effect of external prestressed truss steel-bar units installed on an unreinforced masonry (URM) wall under out-of-plane loadings. The key components of this new retrofitting method are prestressed vertical and diagonal bars. The prestressed vertical bars induce a prestressing force onto the horizontal section of the URM wall and the diagonal bars resist lateral loadings. Reverse cyclic tests were conducted on a full-scale URM wall as a control specimen and URM walls retrofitted in-plane and/or out-of-plane (parallel to short intersecting walls). The test results showed that the specimen strengthened using the new technique was superior to the control specimen in terms of seismic performance, including lateral load resistance, stiffness, energy dissipation and restrained slip of the entire specimen. Two units installed on short intersecting walls exhibited the same shear strength as four units installed on the in-plane and in-plane retrofitted masonry walls. The out-of-plane masonry specimen demonstrated the best performance. It was confirmed that aligning the retrofitting method based on the loading direction was effective, despite the lower axial load level.

The origami principle of folding planar sheets into functional three-dimensional devices promises a future with increased compactness and reconfigurability of biomedical robots. To inspire new origami-based biomedical robots, we highlight two categories of origami patterns that are applicable to build compact actuators, deployable stents, and minimally invasive surgery devices. Due to the requirements in system integration, biocompatibility, and payload capability, the conventional paper-based origamis are converted to physical robots by replacing the zero-thickness facets and zero-width folds with thick panels and flexible hinges, respectively. Therefore, the physical origami-based robots become inhomogeneous, making it more complex and challenging to analyze their mechanics. So far, no such model can analyze the mechanics of any physical origami robot. Herein, we propose a computational model that discretizes the continuous structures into truss and spring elements to fulfill this goal. Based on the model, we simulate the identified origami structures under various boundary conditions to investigate their application in biomedical scenarios. This article is expected to accelerate the design iteration of new functional biomedical origami robots.

The geometry of the structure and internal bar forces under varying service load situations or prestressing actually impact on the structure’s serviceability. Or else, prestressed cable structures ...

The challenge is to search out the economic structure system of high-rise buildings within the Indian scenario. This document covers numerous steel systems: moment-stabilizing frame system, composite frame system, luggage rack system with stabilizing belt, structural wall frame system, and frame tube system. Once coming up with multi-storey buildings, truss systems, cluster piping systems for high-rise buildings, lateral hundreds (wind or unstable loads) are principally chargeable for demolition, determining structural systems for high-rise buildings. To form the drift as slight as possible, the beams and columns should be more stiffed. In an exceedingly building with a bit of floor range, the lateral load seldom affects the rise within the building and, therefore, increases size. The part structure considers the aspect load and the doable arranging of the structure. In alternative side load resistance systems beneath study, the force frame’s side displacement is the highest. The lateral displacement of the double frame is the smallest, and the lateral displacement of the slippery wall system is slightly beyond that of the double system.

Truss is a structural twin of kinematic mechanism. A truss is specially used to support the roof, rocket launch structures, telecom towers, and bridges as structural entities. They have a great tendency to bear heavy load and withstand impact loading conditions. In this paper, spatial truss formula “n = 2j-3” is derived using a simple kinematic approach and Grubler criterion. A primitive hit and trial method based on stability and mobility is used to separate stable trusses followed by mathematical analysis. In addition, a modification of Grubler criterion is introduced in this work to especially understand and derive the truss equation. Connectivity constants are incorporated further evolve the understanding of stability and mobility in 2D structures. Finally, the complex Grubler criterion is reduced to the simple truss equation.

The dynamic behavior of tall building structures is unpredictable under lateral loads. The key concern of tall building design is controlling deflections under lateral loads like earthquake loads or wind loads. There are many structural forms to resist lateral loads; the outrigger system is one of the best structural forms for effective lateral load resistance in tall buildings. Since the location of the outrigger enormously influences the dynamic behavior of tall structures, the present research focused on finding the optimum location of the outrigger along with the height of the structures. For this contest, a numerical study is carried out with five structural models of different aspect ratios. The aspect ratio of the models considered is 0.91, 0.61, 0.45, 0.36 and 0.30. All five models are designed as per Indian codes, IS456, and IS1893. For the observation of the dynamic performance of the five models, the outrigger truss without any belt truss is placed at different heights of the building. For each position, the dynamic performance of the 3D structure is observed. The study is made to compare the reductions in displacements, inter-story drifts, and overturning moments for the buildings with and without outriggers. This study focus on the change of the position of the outrigger for greater resistance to lateral loads depending upon the aspect ratio of the buildings. The analytical results have been studied to find out the optimum location of the outrigger, along with the height of the structures with different aspect ratios. It was concluded that the optimum position of outrigger truss without belt truss is at 65 to 80% of the height of the building for aspect ratios between 0.45 and 0.95.

IEEE Keyword search problem has been widely studied to retrieve relevant substructures from graphs. However, existing approaches aim at finding compact trees/subgraphs containing the keywords, and ignore density to evaluate how strongly and stablely the keyword nodes are connected. In this paper, we study the problem of finding cohesive subgraph containing query keywords with high density and compactness, and formulate it as minimal dense truss search problem based on k-truss model. However, unlike ${k}$-truss based community search that can be efficiently done by local search from a given set of nodes, this problem is nontrivial as the keyword nodes to be included in the retrieved substructure is previously unknown. To tackle this problem, we first design a novel hybrid KT-Index that keeps the keyword and truss information compactly to support efficient search of dense truss with the maximum trussness ${G_{den}}$. Then, we develop a novel refinement approach to extract minimal dense truss from ${G_{den}}$, by checking each node at most once based on the anti-monotonicity property of k-truss, together with several optimization strategies including batch based deletion, early-stop based deletion, and local exploration. Extensive experimental studies on real-world networks validated the effectiveness and efficiency of our approaches.

The results of the survey of steel trusses covering six industrial buildings are presented. In particular, the presence of various forms of defects of compressed rods was revealed: general bends in the plane and out of the plane of the truss, local perishes of the shelves - grinding and grinding. The necessity of strengthening the rods for further operation of the structures is determined. The proposed technical solutions for strengthening deformed rods are presented. When developing technical solutions, we tried to achieve, if possible, compensation for the damaged part of the cross-section (for locally damaged rods) and bringing the axis of the repaired rod to the design position (for rods with common bends). To confi rm the eff ectiveness of the proposed solutions, experimental studies were conducted. A brief analysis of the results is given.

Prefabricated buildings are green and environment-friendly, with high construction efficiency. Concrete-filled steel pipe structures have high bearing capacity and strong deformation ability. Special-shaped column frame structures of prefabricated concrete-filled circular steel pipe with built-in lattice can give full play to the advantages of prefabricated buildings and concrete-filled steel pipe structures, with the advantage of high space utilization rate of special-shaped column structures. In order to study Seismic performance of frame in special-shaped columns of prefabricated concrete-filled circular steel pipe with built-in lattice, a full-scale middle frame model specimen with two floors and two spans was designed, and the failure mechanism of the specimen was obtained by low-cycle loading test. The hysteretic performance, deformation capacity, energy dissipation capacity and stiffness degradation of the specimen were analyzed. The results showed that the failure mechanism of the prefabricated concrete-filled steel tubular special-shaped column is a typical beam hinge mechanism, which meets the design requirements of “strong column and weak beam”. The special-shaped columns frame of built-in concrete-filled circular steel pipe has full hysteretic curve, good ductility and energy dissipation capacity, and stable stiffness degradation. When the specimen is damaged, the inter-story drift angle reaches 1/23, which is much higher than the limit requirement of elastic–plastic inter-story drift angle of 1/50 under strong earthquake. The existence of built-in concrete-filled steel pipe changes the bearing mechanism of the structure. After the external concrete falls off, the internal force of the structure redistributes, forming a stress system of built-in concrete-filled steel pipe truss. The post-cast joint between overlapping precast column and superposed beam and grouting connection joint between precast column and column sleeve are not damaged, and the fabricated joints are safe and reliable.

Recently, the collapse of space truss structures has been a public concern, often triggered by local damages of key components. The enhancement effects of buckling-controlled methods on the damaged members of space truss structures are systematically investigated by the detailed numerical analysis. Different local damages are introduced to the members to discuss the influence of damage positions and levels on the bearing capacity and displacement ductility. The sensitivity analysis is also performed to select representative damage modes. Compressive sleeve columns are designed and simulated for the damaged tubes, and the simulation method is verified by the reference tests. Moreover, parametric analysis is carried out to analyze the influence of the protrusion length, stiffness ratio and gap on the post-buckling behavior of members, including the failure mode, bearing capacity, enhancement effect and displacement ductility. Different designs of the outer tubes are proposed for the inner tubes with various damages. The principle in this work can effectively guide the reinforcement of the damaged members.

This paper describes a simple analytical tool for the calculation of the shear strength of r.c. rectangular members with shear reinforcement and subjected to only truss mechanism. The proposed method considers simplified stress fields and evaluates the shear strength of members subjected to axial force, bending moment and shear force by means of the application of the static theorem of limit analysis. Unlike most of the formulations proposed in codes and in other research studies, the proposed method considers a single physical model to explain the resistance to axial force, bending moment and shear force, and simultaneously satisfies the equilibrium under all the above internal forces. The paper identifies basic points of the N-M-V ultimate domain and reports relations and procedures to calculate the values of the internal forces of these points as well as the internal forces of the points in between. The method is applied to a set of beam and column members and a comparison is drawn between the shear strength resulting from the simplified method and that from a more complex non-linear mathematical program proposed in the past by the same author. Finally, to prove the value of the method and define the field of reliable application, the proposed method is applied to members tested in laboratory by other researchers and characterised by different geometric and mechanical properties. The obtained results are also compared with those deriving from other methods present in the literature.

Full-span overhead sign support structures can be found along any major highway across the US. Such structures experience different wind loading scenarios varying with time. As a result, these structures start to build up fatigue cracks within their members near the end of their fatigue life. Due to economic realities, the needed routine fatigue inspections on such highway structures can not be performed regularly. This paper is intended to present a comprehensive tool to accurately predict the remaining fatigue life of full-span overhead highway sign support structures subjected to a long and sustained wind fluctuation. Synthetic wind time histories were developed by superimposing cosine waves over a range of frequencies of 3–300 Hz and randomly generated phase angles. Kaimal spectrum was utilized to build a database of wind time histories for each daily mean wind speed along a period of 45 years in the State of Kansas. Moreover, each wind time history was modified to capture both the mean speed and high speed in each given day. After that, the wind speed vs. the number of cycle relationship, for a given time span, was extracted from the synthetic wind time history using the Rain Flow counting technique. Fatigue evaluations were conducted using axial truss member stresses extracted from a finite element solution corresponding to each wind speed in any given time range. Potential fatigue failure was assessed for each structural member after amplifying the stress range using an average dynamic amplification factor generated by integrating the frequency-response curve of harmonic excitations. These assessments evaluate the ratio of consumed fatigue cycles to ultimate fatigue cycles using Miner’s rule to estimate the fatigue life. A computationally affordable simulation package was developed to carry out the generation of wind time histories, cycle counting, structural modeling, and fatigue life calculations. This package was used to evaluate the fatigue life of a non-cantilever sign structure in Wichita, Kansas. The software predicted the end-of fatigue life of two members in this structure. Accordingly, inspections of these two members revealed the existence of unnoticed severe fatigue cracks while other members did not show any sign of distress.

The researched truss of the Gothic Church of St. Bartholomew in the village of Mladočov is one of the examples of the use of the historical Czech length units of measurement; in this case, the Gothic and Baroque part of it. At the same time, it analyzes the proportional relationships between the individual elements of the truss. The structural analysis in relation to current standards points to the fact that the original design of the structure based on geometrical and proportional principles satisfy the reliability conditions defined by current European standards for structural design.

When the truss structure is reinforced in operating state the additional force is given to it.We propose the method for determining the reasonable magnitude of additional force to reduce the internal force by minimum condition strain energy of truss

The Sepanjang bridge is a steel frame bridge that connects Sepanjang Sidoarjo Park and Surabaya's Mastrip Road. Redesigned to determine whether with different types and shapes of frames can get a bridge that remains strong to bear the burden carried but more economical, namely by reducing the steel profile used. Analysis and modeling of the bridge structure along will be carried out using SAP2000 software. Modeling is done with the framework of existing conditions and order configuration results and configuration optimization. The result with the right configuration will provide better efficiency, so that the optimization of the steel profile reduction can be done on the Sepanjang Bridge. Keywords

PurposeIn this paper the use of classical strain measures in analysis of trusses at finite deformations will be discussed. The results will be compared to the ones acquired using a novel strain measure based on the Hyperbolic Sine function. Through the evaluation of results, algebraic development and graph analysis, the properties of the Hyperbolic Sine strain measure will be examined.Design/methodology/approachThrough graph plotting, comparisons between the novel strain measure and the classic ones will be made. The formulae for the implementation of the Hyperbolic Sine strain measure into a positional finite element method are developed. Four engineering applications are presented and comparisons between results obtained using all strain measures studied are made.FindingsThe proposed strain measure, Hyperbolic Sine, has objectivity and symmetry. The linear constitutive model formed by the Hyperbolic Sine strain and its conjugated stress presents an increasing stiffness, both in compression and tension, a behavior that can be useful in the modeling of several materials.Research limitations/implicationsThe structural analysis performed on the four examples of trusses in this article did not consider the variation of the cross-sectional area of the elements or the buckling phenomenon, moreover, only elastic behavior is considered.Originality/valueThe present article proposes the use of a novel strain measure family, based on the Hyperbolic Sine function and suitable for structural applications. Mathematical expressions for the use of the Hyperbolic Sine strain measure are established following the energetic concepts of the positional formulation of the finite element method.

The geometric agreement, commonly hailed as load-transferring paths within bridge structures, is significantly crucial to the bridge structural mechanical performance, such as capacity, deformation, and collapse behavior. This paper presents a methodology dependent on alternative load paths to investigate the collapse behavior of a double-pylon cable-stayed bridge with steel truss girders subjected to excess vehicle loading. The cable-stayed bridge with steel truss girders is simplified using a series-parallel load-bearing system. This research manifests that the enforced vehicle loading can be transferred to alternative paths of cable-stayed bridges in different load-structure scenarios. A 3-D finite element model is established utilizing computer software ANSYS to explore the collapse path of cable-stayed bridge with steel truss girders, taking into account chord failure, loss of cables together with corrosion in steel truss girders. The results show that chord failures in the mid-portion of the mainspan result in brittle damage in truss girders or even sudden bridge collapse. Further,the loss of long cables leads to ductile damage with significant displacement.The corrosion in steel truss girders has a highly slight influence on the collapse behavior of cable-stayed bridge. The proposed methodology can be reliably used to assess and determine the vulnerability of cable-stayed bridge with steel truss girders during their service lifetime, thus preventing structural collapses in this type of bridge.

Trusses are everywhere; they are used in bridges, antenna towers, cranes, even in parts of the International Space Station. And for good reason, they allow us to create strong structures while using materials in very efficient and cost-effective way. Trusses it is essentially a rigid structure made up of a collection of straight members. The type of truss depends on how the horizontal and diagonal beams are arranged.

The performance of bridge expansion devices (e.g., bearings or expansion joints)is a major concern for the operation department. A mechanical analysis model can be used to accurately analyze the influence mechanism of major factors and evaluate the working performance of bridge expansion devices with structural health monitoring data. Considering the nonlinear characteristics of bearing friction, a friction hysteresis model was established in this study to analyze the behavior of the bearing longitudinal displacement (BLD) under thermal excitation. The friction hysteresis model can describe the motion path of the BLD under periodic temperature. The variation in the model parameter is defined as an evaluation index that can reflect the degradation in the working performance of the bearing. The periodic change in the temperature is the driving force for developing the friction hysteresis model, and the calculation of the temperature-induced BLD is critical in extracting the evaluation index. Therefore, a calculation formula for the BLD of the steel truss bearing was derived considering the temperature gradient. Finally, the application of this method was verified through the temperature and BLD monitoring data of a multispan continuous steel truss arch bridge. The results showed that the evaluation index variance can describe the maximum bearing friction increase. However, the proposed approach is primarily based on thermal excitation, because of which it cannot assess the bearing working performance if the uncertainty in the friction hysteresis model is introduced by other types of excitations (e.g., vehicle excitation).

The corrosion environment of a steel truss bridge significantly shortens its service life, particularly the chemical pollution in the air. A linear corrosion prediction model is proposed based on Miner’s linear cumulative damage concept to solve the difficulty of implementing accelerated corrosion tests. Moreover, an equivalent fatigue test is designed in combination with the corrosion prediction model. The results indicate that the bridge’s fatigue resistance can meet the design requirements when the corrosion environment is not considered. When the corrosion effects are jointly considered, the fatigue durability of the bridge is insufficient. With the increase in fatigue cycles, stiffness degradation presents a three-stage trend. The intermediate stage is a gentle development stage from the fatigue test results, accounting for approximately 80% of the total life cycles. Finally, a fatigue damage prediction model considering corrosion factors is established, and the law of fatigue damage and stiffness degradation of the structure under a corrosive environment is determined.

Based on the theoretical results obtained in the article [17], here the analysis of the influence of various design parameters on the own weight and cost of metal of truss beams with two posts is carried out. An optimal parameter has been obtained that makes it possible to reduce the calculated bending moment in the cross section of a truss beam with two struts.Method. By equalizing the bending moments in various design sections of the truss beam, the internal force factors are reduced. The corresponding equation for optimizing the parameters of the beam has been drawn up and a formula has been obtained to determine the optimal parameter of the structure as a whole.Result. Using the example of numerical calculations, a decrease in the calculated bending moment by 14% compared to truss beams without optimization is shown.Conclusion. The proposed method and algorithm testify to the efficiency and rationality of the obtained optimal parameter of the structure as a whole.

The outrigger structural system is one of the horizontal load resisting systems. In this system the belt truss ties all the external columns on the periphery of the structure and the outriggers connect these belt trusses to the central core of the structure thus restraining the exterior columns from rotation. The shear wall was implemented to oppose lateral loads. To complete these characteristic the Outrigger & wall belt system used in the structure. In this project a G+10 Storey structure has analysed using seven different cases named as RA1 to RA7-OTB. 1 to 7 indicates single outrigger system, shear core outrigger system truss belt support system with optimized trusses, at various locations under seismic zone III. The built up area used for various case as 315 sq. m. After performing result analysis, the comparative analysis of all the cases shows that the most efficient case for the above study is Case RA4. Here for efficiency of the project, two types of optimized truss belt support which has performed well and observed as most optimized and correspondingly minimum in all the cases. Keywords: Truss wall belt support, core wall belt support, outrigger, wall belt, CSI-ETABS, multi-storey

A steel truss is a preferred solution in large-span roof structures due to its good attributes such as lightweight, durability. However, designing steel trusses is a challenging task for engineers due to a large number of design variables. Recently, optimization-based design approaches have demonstrated the great potential to effectively support structural engineers in finding the optimal designs of truss structures. This paper aims to use the AdaBoost-DE algorithm for optimizing steel roof trusses. The AdaBoost-DE employed in this study is a hybrid algorithm in which the AdaBoost classification technique is used to enhance the performance of the Differential Evolution algorithm by skipping unnecessary fitness evaluations during the optimization process. An example of a duo-pitch steel roof truss with a span of 24 meters is carried out. The result shows that the AdaBoost-DE achieves the same optimal design as the original DE algorithm, but reduces the computational cost by approximately 36%.

Concentrically braced frames have complete truss behavior properties in which the structural elements are governed by axial forces in the elastic region. However, in a large earthquake action, inelastic deformation occurs to the brace elements and the connections, which causes a decrease in the internal resistance force and the energy dissipation capacity. Development of the possibility to return to the seismic resistance system without residual strain is necessary to solve this problem. In this paper, the steel frame of the superelastic SMA wire bundle brace with the proper type of connection is set up and an experimental test of one-half scale model is conducted to confirm its seismic applicability. This system effectively creates a system with an adjustable amount of re-centering, which can arguably be used in a wide spectrum of new and existing building structures.

Jembatan merupakan fasilitas penghubung suatu wilayah yang berfungsi untuk fasilitas penunjang ekonomi wilayah tersebut. Jembatan memiliki fungsi krusial disuatu wilayah untuk melakukan aktifitas dan pekerjaan sehari-hari seperti, perdagangan, sosial, politik & lain sebagainya. Di Jawa timur, tipe rangka yang digunakan banyak menggunakan rangka tipe Warren, sehingga diperlukan perbandingan analisis dengan tipe jembatan lain untuk menentukan tipe jembatan yang paling efisien. Pada analisis ini dipakai jembatan tipe Pratt. Analisis ini bertujuan untuk membandingkan rasio kekuatan terhadap berat struktur total. Dari output analisis didapat dalam Jembatan tipe Warren rasio kekuatan terhadap berat struktur adalah 3,417 sedangkan jembatan tipe Pratt mempunyai rasio kekuatan terhadap berat struktur adalah 3,358. Besar defleksi yang terjadi pada struktur rangka Warren adalah sebesar -0.0528 lebih kecil daripada jembatan tipe Pratt yaitu -0.0571. Berat dari struktur jembatan tipe Warren memiliki berat sebesar 18042,4 kg, sedangkan jembatan tipe Pratt sebesar 19023 kg. Berdasarkan hasil analisis yang didapat, maka ditunjukkan bahwa rasio kekuatan dan berat struktur jembatan tipe Warren adalah 3,417 dan tipe Pratt sebesar 3,358.

With the development of engineering structures towards the direction of large-scale, light-weight and multi-function, truss structures are utilized widely in the aerospace and civil sectors due to their outstanding advantages, e.g. light weight, large stiffness ratio and high packaging efficiency. Meanwhile, investigating the nonlinear dynamic mechanism and developing vibration control strategies for large space truss are of practical importance and give rise to interesting scientific issues. Finite element method is a popular approach but brings great challenges to the nonlinear dynamic analysis and vibration controller design of truss structures due to the high degree of freedom of the full-scale finite element model. Therefore, the equivalent continuum modeling methodology becomes one of the most important developing trends to address these difficulties and is of high-efficiency especially for the nonlinear dynamic analysis. In the present paper, the research status about the equivalent continuum modeling of truss structures is sorted out including equivalent modeling methods (the energy equivalent method, the homogenization method, the displacement equivalent criterion, etc.) together with their advantages and drawbacks. Issues on static, dynamic, and buckling analyses of various structural styles (beamlike truss, platelike truss, hoop truss, etc.) with different connection joints are discussed. More specifically, the research progresses on equivalent nonlinear continuum modeling and the design of vibration control law of the large truss structures are investigated, respectively, and the gap on the nonlinear analysis and vibration control is summarized for the existing researches. Additionally, comment, perspective and opportunity are proposed which could be valuable for the future developments of equivalent continuum modeling and vibration control of the large truss structures.

Top-t queries, which return t results with the highest scores according to the user’s preferences, have been extensively studied. However, many studies often fail to take into account the social relationships among users, and close social relationships usually guarantee the consistency of users’ preferences. Many real-world applications, such as community-based product recommendation services, require such queries. In this paper, we propose a new problem: the k-truss community most favorites querying problem based on user top-t favorites. Specifically, both the k-truss community and the corresponding most favorite object are retrieved. We first present the baseline solution to the problem. The main idea is to find the same object in the top-t favorites of the users in the social network and build the k-truss community for these users with the same preferences. Furthermore, we propose a reverse query algorithm to speed up the processing of the k − t CMF querying problem by filtering users in the social network. The experiment results on both real and synthetic datasets significantly demonstrate that the proposed solutions are efficient and scalable.

Unreinforced masonry (URM) walls, found in most historical buildings in Indonesia, are relatively brittle with wide variety of material properties. The behaviour of URM walls is very complex, especially when subjected to seismic excitation. In this research, a finite element modelling was set up in order to analyse the seismic performance of URM wall experimental test units, with and without strengthening material. The analysis was conducted using SAP2000 computer program. Three dimensional solids and springs as link connectors were assigned to represent the masonry behaviour. This research aims to compare results obtained from the computer analysis and the previously conducted laboratory experiments. The effectiveness of Kevlar fibre material, which was installed on both wall surfaces and modelled as truss element was also investigated. It was found that the failure mechanisms shown by the SAP2000 model was similar to the laboratory test results. The use of Kevlar Fibre as strengthening material was found able to significantly increase the stiffness and shear capacity of the URM wall.

In the extension project of the China National Academy of Painting, the radial spherical plain bearing (RSPB) is used in a structural joint with an inserted plate. This new structural RSPB joint has complicated mechanical behaviors and universal rotational performance. In this work, the simulation and experiment methods were used to investigate the RSPB joint mechanical properties (uniaxial ultimate bearing capacity, failure mode) and reliability. Furthermore, the out-of-plane rotational performance was studied with eight finite models for the application. According to FEA and test results, this new RSPB joint has functional mechanical properties. It is useful in steel truss structures and provides a possibility for engineers to design hinge joints in building structures.

In this paper, the isolation performance of truss string structure on rubber bearings considering relative rotation between the upper and lower surfaces of the bearings is studied. Through the test and finite element analysis, the following conclusions are obtained: the initial rotation angle has a great influence on the horizontal stiffness of the isolation bearing. In practical engineering, the loss of prestress, the change of temperature and general vertical loads will produce rotation angle between upper and lower surfaces of the bearings. Therefore, the numerical analysis of the truss which consider rotation angle of the rubber bearings is carried out. The results show that the horizontal acceleration responses of the truss decreases, and the displacement of the isolation bearing exceeds the code limit. Therefore, the practical engineering structure should consider the influence of the rotation angles.

To mitigate the deficiency of the conventional steel frames, a novel steel frame system using rocking truss (SFWRT) and self-centering energy dissipative devices (SCED) was developed. The SCED consists of structural members, pre-tension tendons, abutting element and friction dissipation devices, which exhibits excellent self-centering and energy dissipation capacity. This new structural system is analyzed using Incremental Dynamic Analysis method (IDA). A scaled earthquake acceleration response spectrum from a specified ground motion was used in this analysis. It is found that the formation of the plastic hinges of the structural components includes four stages: emergence, developing, degradation and completely bearing capacity loss. A comparative study is also made to investigate the development of these plastic hinges under different ground motions in both traditional steel frame and SFWRT. The results for evaluating the lateral collapse resistance capacity indicate that the rocking truss can significantly decrease the structural dynamic response and improve the seismic performance of buildings. The collapse probability curves of the steel frame and SFWRT based on three limit states are compared. It is found that the rocking truss is helpful to reduce the collapse probability under earthquakes. The damage of the steel frame as well as the expected loss of the main structure after an earthquake can be significantly reduced with the help of rocking truss, which would also reduce the repair cost and improve the structural resilience under earthquakes significantly.

The present work deals with the improvement of the seismic performance of a Single Story-Single Bay Special Truss Moment Frame (STMF) by incorporating Shape Memory Alloys (SMAs) as dissipation devices in the special segment, which can recover their initial geometry after mechanical distortion by unloading through the phase transformation (martensitic-austenitic phase). STMFs were initially designed with a special segment located in the middle of the truss to dissipate the input energy through the formation of plastic hinges at the four corners of the chord members. This mechanism is replaced with the input energy dissipation through the SMA deformation in a pin-ended special segment. In what follows, the frame at hand is examined incorporating SMA bars per diagonal of either 0.025 m or 0.035 m in diameter, restrained against buckling, simulated via a 4-DOF mechanical model consisting of two lumped masses, under selected ground motions. To further evaluate the performance of the frame with SMAs incorporated and at the same time verify the model, a non-linear dynamic time-history analysis is conducted using SeismoStruct Finite Element software. The response of the proposed system is compared with the one of the conventional one. Results show that the proposed system leads to a decrease of the maximum displacement and potentially allows a much lighter construction.

Concrete-filled rectangular steel tubular (CFRST) composite truss bridge is a new type of structure composed of a CFRST truss and concrete deck slab. This new type of bridge has the advantages of high structural force-transferring efficiency, rapid assembly construction speed and excellent total life cycle, which meets the construction concept of green, recyclable and sustainable development. Due to the broad application prospects, experiment on the flexural behavior of CFRST composite truss bridge in the negative moment region was reported by authors previously. This paper thus presents a finite element analysis (FEA) modelling verified by the reported test data to further investigate the detailed analytical behavior of this structure. The structural response and failure mechanism of CFRST composite truss beam in the negative moment region are studied. In addition, the important structural design parameters on the flexural performance of the CFRST composite truss beam are also investigated, including the height to span ratio, the brace-to-chord wall thickness ratio, the reinforcement ratio of steel reinforcements and prestressed tendons and the strength grade of concrete infill in chords. Finally, the reasonable structural design parameters range are proposed for the optimum design of the CFRST composite truss bridge.

The challenge that structural optimization tasks pose by dint of their highly non-linear design constraints and complex solution domains has spurred both the implementation and development of many novel metaheuristic algorithms over the past two decades. In this study, the very recently proposed political optimizer algorithm has been implemented in the context of structural optimization. Inspired by the multi-phased political process in parliamentary democracies, the algorithm efficiently balances between exploration and exploitation by logically dividing the population of search agents into political parties that compete for constituency (electoral district) domination. This competitive-based population partitioning scheme ensures that enough of the search space is thoroughly investigated for the global optima all the while maintaining algorithmic speed and efficiency. Moreover, a local search mechanism known as the recent past-based position updating strategy (RPPUS) provides for an effective exploitation strategy where every search agent is allowed to learn from its previous behavior and hence collectively guide the population towards better solutions and away from worse ones. To quantitatively assess the performance of the algorithm, three planar trusses (10 bar, 18 bar, and 200 bar) and four space trusses (22 bar, 25 bar, 72 bar, and 942-bar) with multiple loading conditions and design constraints have been considered. Results show that for small/medium-scale structural systems, the PO algorithm outperforms all previously proposed state-of-the-art optimization methodologies in all aspects may it be final optimized weight, algorithmic stability, or convergence speeds, and that for larger structures excellent performance is still maintained but a certain, yet acceptable, extent of algorithmic instability is manifest. Based off these findings, future research into the PO algorithm as an efficient structural optimizer is strongly recommended.

A new type of suspension bridge is proposed based on the gravity stiffness principle. Compared with a conventional suspension bridge, the proposed bridge adds rigid webs and cross braces. The rigid webs connect the main cable and main girder to form a truss that can improve the bending stiffness of the bridge. The cross braces connect the main cables to form a closed space truss structure that can improve the torsional stiffness of the bridge. The rigid webs and cross braces are installed after the construction of a conventional suspension bridge is completed to resist different loads with different structural forms. A new type of railway suspension bridge with a span of 340 m and a highway suspension bridge with a span of 1020 m were designed and analysed using the finite element method. The stress, deflection of the girders, unbalanced forces of the main towers, and natural frequencies were compared with those of conventional suspension bridges. A stiffness test was carried out on the new type of suspension bridge with a small span, and the results were compared with those for a conventional bridge. The results showed that the new suspension bridge had a better performance than the conventional suspension bridge.

In this paper Analysis and Design of different Structural elements of the football stadium are presented, with particular emphasis on the Combination of Steel Truss without and with Shell roof cover and its interȧction with the underlying reinforced concrete structures. The Football stadium considered for the study is of rectangular plan, with 85 m width and 140 m length and height of 19.5 m. The plan of Football Stadium is generated in AutoCAD 2016 software. The Stadium structure is composed of special moment – resisting framed. Wind velocity is taken as 39 mph and Seismic zone IV in this study. The proposed stadium is analysed using Equivȧlent static and dynamic ȧpproach by Reṣponse ṣpectrum ȧnd Time Hiṣtory ȧnȧlysis. In anȧlysing the ṣtructure, 21 load combinations are used. The grandstand ṣtructure is made of reinforced concrete and the roof is of ṣtructural steel using Pipe and Tube sections. Deȧd loȧdṣ, live loȧdṣ, wind ȧnd ṣeismic loȧdingṣ data are considered bȧsed on IS-875 (PART 1-3) 1987 ȧnd IS:1893 (Part 1):2016. IS456:2000 and SP16:1987 code is used for Design of R.C.C components such as Beȧm, Column, Seating Platform, Footing and IS 800:2007 code is used for Design of End Beȧring Plate connection with Truss member. Analysiṣ of truss and other elements is carried out with software program of Staad. Pro V8i SS6 and also the designs are carried out as per provisions of relevant Indian standards. On introduction of Shell-like roof for Open Stadium which is used not only to protect the Game from Glare of Sunshine and Rain but also appears unique and attractive. From the obtained results it is observed that the displacement due to Wind action in both X and Z direction reduces significantly by the introduction of Shell roof. Also, due to RSA and THA there is reduction in the displacement on introduction of Shell-like roof to an Open Stadium. Keywords

The composite slab with steel trusses is composed of precast bottom plate and cast-in-place concrete. In engineering applications, cracks often appear in the bottom plate before casting the upper concrete, which even leads to the failure of the composite slab. To improve the crack resistance of the slab, a composite slab with additional steel trusses is proposed; that is, on the basis of the original longitudinal steel trusses, the transverse steel trusses are added. Static test and numerical analysis were carried out on the bottom plate of the new type of composite slab with the additional transverse steel trusses. The experimental and analytical results show that the load level of the plate with additional steel trusses can be increased by 33% under the normal service limit state; the deflection of the plate is significantly reduced and the crack development is effectively controlled, which illustrates that the new type of composite slab can improve the bearing capacity, increase the bending stiffness, and enhance the crack resistance effectively.

In past decades, shear walls and x bracing are one of the most appropriate and important structural component in multi-storied building. Therefore, it is very interesting to study the structural response and their systems in multi-storied structure during lateral load i.e earthquake loading. Shear walls and belt truss contribute the stiffness and strength during earthquakes which are often neglected during design of structure and construction. The scope of present paper is to study the effect of seismic loading on placement of belts truss in building at different alternative location. This study shows the effect of belts truss and bracing belts truss which significantly affect the vulnerability of structures. In order to test this hypothesis, RCC building was considered with and without belts truss at different location. The aim of the paper is to detail and conceptualize the varied configurations of belt truss structures system and to integrate current structures into longer structures by use of belt truss system at different location. Additionally, various advantage and disadvantage associated with outriggers and belt truss system also are discussed in this paper. A close of literature review within the field of Outrigger system is applied and therefore the summary on belts truss and gaps encountered within the study are listed during this paper. This paper introduces belt truss at different location. In which, using the belt truss structural within the RCC building so as to extend the performance of the building under the earthquake load and wind loads is studied. Concept of belt truss as Virtual outrigger is reviewed within the paper.

In order to obtain a new structure of beam flexure hinge with good performance, the flexure hinge based on the X-lattice structure is researched in this paper. The truss model in the finite element method is used to model the 6-DOF compliance of the flexure hinge based on the X-lattice structure. The influence of structural parameters on the compliance and compliance ratio of flexure hinges is analyzed based on this model, and the performance is compared with the traditional beam flexure hinge of the same size. In order to design a flexure hinge based on the X-lattice structure with good comprehensive performance, this paper proposes an intelligent structure optimization method based on a genetic algorithm. The feasibility of the optimization algorithm is verified by an example.

Постановка задачи. Разыскиваются аналитические зависимости прогиба и смещения опоры плоской фермы решетчатого вида от числа панелей. Ферма имеет сдвоенную решетку, прямолинейный нижний и приподнятый в средней части верхний пояс. Результаты. Для двух видов нагружения по формуле Максвелла-Мора получены аналитические зависимости прогибов конструкции от нагрузки, размеров и числа панелей. Для обобщения серии частных решений с различным числом панелей ферм на произвольный случай использован метод индукции и аналитические возможности системы компьютерной математики Maple. Для некоторых решений получены асимптотические приближения. Показано распределение усилий в элементах фермы. Выводы. Полученные формулы могут быть использованы в задачах оптимизации и как тестовые для оценки приближенных численных решений. Выявлены случаи геометрической изменяемости фермы при числе панелей, кратном трем. Приведен алгоритм выявления соответствующего распределения возможных скоростей шарниров. Statement of the problem. Analytical dependences of the deflection and displacement of the support of a flat lattice truss on the number of panels are being sought. The truss has a double lattice, a rectilinear lower belt and an upper belt raised in the middle part. Results. For two types of loading, according to the Maxwell-Mohr formula, analytical dependences of the deflections of the structure on the load, dimensions and number of panels are obtained. To generalize a series of particular solutions for trusses with different numbers of panels for an arbitrary case, the induction method and the analytical capabilities of the Maple computer mathematics system were used. For some solutions, asymptotic approximations are obtained. The distribution of forces in the rods of the structure is shown. Conclusions. The obtained formulas can be used in optimization problems and as test ones for evaluating approximate numerical solutions. Cases of geometric variability of the truss with the number of panels being a multiple of three are revealed. An algorithm for identifying the corresponding distribution of possible velocities of the joints is presented.

In this paper, a cross-section contribution analysis (CSCA) method is proposed to optimize the size of a truss frame. A finite element model of the initial truss frame was established to analyze the static-dynamic stiffness and the full load strength. The reliability of the model was then verified by experiments. An improved wireframe model was obtained from the secondary design of the topological conceptual model, and the contribution rate (CR) of each tube to the performance was analyzed. A “modular line” was defined to modularize the frame tubes based on the cross-section CR (CSCR). The performance and light weight of the modular frames (MFs) with different tube layout schemes were studied. The results of modular size optimization show that the optimized truss frame for small electric vehicles (EVs) reduces the weight and improves the performance significantly. In addition, this method can have better results in continuous variable optimization (with non-standard tube size) as a reference for industry. In discrete variable optimization (with standard tube size for manufacturing feasibility), the method could greatly shorten the development cycle and lead to production rapidly.

Generative design refers to the automated design of components through the use of computer-aided engineering (CAE) tools. This is an enabling technology which allows reduced lead times in component design, particularly for custom and unique parts; improved certification of components; efficient exploration of the design space; and results in optimised design outcomes. Topology optimisation (TO) is a systematic tool for defining efficient material distributions for given boundary conditions, whereas shape optimisation (SO) is useful for refining identified part geometries with respect to design constraints. These qualities make TO and SO suitable for automating the embodiment and detailed design phases respectively for use in generative design. However, integration of these tools is hindered by challenges in the parameterisation of TO solutions, which are typically manually resolved. This manual resolution imposes a limit on the rate in which data can be generated as well as the scope of the solution space. In response to this challenge, a novel parameterisation method is proposed to directly integrate topology and shape optimisation to achieve an automated design process. The benefits of the proposed method are reduced computational cost and improved automation, which is suitable for investigating a large number of potential solutions and selecting and refining an optimal design for a given loading condition. The proposed method has been used within this paper for the design of 2D trusses as a proof of concept.

The article focuses on the oldest surviving I-type portico houses located in the Vistula Delta, which were built in the 17th and 18th centuries. The study describes the houses’ origins, structure, details of roof structures and technical condition, and it also includes numerical modelling of a roof truss and its mechanical analysis. Numerical models of the roof trusses are defined and analysed by means of the finite element method. Global sensitivity analysis with the use of the polynomial chaos expansion method is used to study the influence of uncertainties in material properties of wood, such as Young’s modulus and the friction coefficient, and also the beam cross-sectional height in the output of the numerical model of the structure. The outcomes show that the uncertainty of beam height exerts the dominating influence on the maximum deflection of the roof truss, hence accurate measurements of geometry are of great importance in the planning of conservation and renovation of such historic structures.

Purpose The purpose of this paper is to study the wire and arc additive manufacturing (WAAM) method and path planning algorithm of truss structure parts, to realize the collision-free rapid prototyping of truss structures with complex characteristics. Design/methodology/approach First, a point-by-point stacking strategy is proposed based on the spot-welding mode of cold metal transfer welding technology. A force analysis model of the droplet is established, which can be used to adjust the posture of the welding torch and solve the collapse problem in the WAAM process of the truss structure. The collision detection model is developed to calculate the interference size between the truss structure and the welding torch, which is used to control the offset of the welding torch. Finally, the ant colony algorithm has been used to optimize the moving path of welding torch between truss with considering the algorithm efficiency and collision avoiding and the efficiency of the algorithm is improved by discretizing the three-dimensional workspace. Findings A series of experiments were conducted to prove the validity of the proposed methods. The results show that the wire feeding speed, welding speed are the important parameters for controlling the WAAM process of truss parts. The inclination angle of the welding torch has an important influence on the forming quality of the truss. Originality/value The force analysis model of truss structure in the WAAM process is established to ensure the forming quality and a collision-free path planning algorithm is proposed to improve forming efficiency.

Thin-walled steel decks have been generally treated as permanent formwork in the routine design of steel-bars truss slabs, and their effects on the time-dependent behaviour of steel-bars truss slabs have not been quantified. The objective of this study was to propose design procedures for the time-dependent behaviour of steel-bars truss slabs accounting for the effects of soffit steel decks. For this purpose, two full-scale slab samples were tested for 9 months, with one slab subjected to non-uniform shrinkage and sustained loading and the other slab subjected to only non-uniform shrinkage. Typical design equations for reinforced concrete slabs and composite steel–concrete slabs were benchmarked against available test results to verify their applicability. Non-linear finite-element models were established to describe the time-dependent behaviour of steel-bars truss slabs, and simplified design procedures were proposed. It was found that the steel-bars truss sample subjected to non-uniform shrinkage had a mid-span deflection accounting for 52·4% of the total deflection; that the design methods in available composite structure standards significantly underestimated the long-term deflections; and that the proposed design procedures well predicted the time-dependent deflections of steel-bars truss slabs by considering the influence of the shrinkage gradient.