Design Of Frame Structures Research Articles

Application of Monitoring System Based on Green Environmental Protection Cable Pipe Protector

In view of the current status of the monitoring system for cable conduit protectors, the green environmental protection and the monitoring system for cable conduit protectors are closely combined to explore the construction of an omnidirectional, multi-level and wide-coverage intelligent cable conduit protector monitoring system to coordinate the advantages of advanced scientific research, technology, instruments and equipment. Based on the research background, the paper briefly introduces the high-temperature superconducting cable monitoring and protection system, and systematically explains the overall function of this research software, frame structure design, communication implementation method, various data record analysis and fixed value research.

Static Pushover Analysis of Beam-Column Joints in Frame Structures

There are many factors influencing the yield mechanism of "strong column and weak beam", which is not required by the current seismic design of frame structures in earthquakes. In this paper, pushover analysis is done by creating ETABS framework model. Firstly, this paper analyses that cast-in-place floor will increase the stiffness and bearing capacity of frame beams. Then, this paper analyses the amplification factor of frame beam stiffness under combined loads. Finally, this paper achieves the effect of "strong column and weak beam" by controlling the reinforcement at the end of the beam.

Risk-based cost-benefit analysis of frame structures considering progressive collapse under column removal scenarios

The decision to design a frame structure to bridge over a column lost due to accidental loading has obvious impacts on construction costs. Moreover, not all structures are potential targets of hazards likely leading to column loss events. In this context, we propose a formulation for risk-based cost-benefit analysis of design for load bridging over failed columns. The formulation combines normal with abnormal loading conditions, treating column loss probability as an independent parameter. The proposed formulation is employed in design of continuous beams, typical RC floors and regular frame structures. The study reveals the conditions for load bridging design in frame structures to be cost-effective. We show that column loss probabilities play a major role in optimal design and reinforcement decisions. The proposed formulation allows optimal design of frame structures addressing competition between failure modes. Under discretionary column removal, competition between local bending and local pancake failures is typical of regular frame buildings, as stronger beams favor pancake compression failures.

Proračun pomičnih okvirnih konstrukcija modificiranim Crossovim postupkom

An original procedure for static design of movable in-plane frame structures is presented in the paper. The presented design procedure was derived using the modified traditional Cross procedure (TCP). The introduction of the TCP modification has resulted in significant improvement of the design algorithm of movable frame structures as compared to TCP, especially as to elimination of the need to conduct greater number of individual iteration procedures, and to solve linear algebraic equation systems.

Massive Access in Cell-Free Massive MIMO-Based Internet of Things: Cloud Computing and Edge Computing Paradigms

This article studies massive access in cell-free massive multi-input multi-output (MIMO)-based Internet of Things and solves the challenging active user detection (AUD) and channel estimation (CE) problems. For the uplink transmission, we propose an advanced frame structure design to reduce the access latency. Moreover, by considering the cooperation of all access points (APs), we investigate two processing paradigms at the receiver for massive access: cloud computing and edge computing. For cloud computing, all APs are connected to a centralized processing unit (CPU), and the signals received at all APs are centrally processed at the CPU. While for edge computing, the central processing is offloaded to part of APs equipped with distributed processing units, so that the AUD and CE can be performed in a distributed processing strategy. Furthermore, by leveraging the structured sparsity of the channel matrix, we develop a structured sparsity-based generalized approximated message passing (SS-GAMP) algorithm for reliable joint AUD and CE, where the quantization accuracy of the processed signals is taken into account. Based on the SS-GAMP algorithm, a successive interference cancellation-based AUD and CE scheme is further developed under two paradigms for reduced access latency. Simulation results validate the superiority of the proposed approach over the state-of-the-art baseline schemes. Besides, the results reveal that the edge computing can achieve the similar massive access performance as the cloud computing, and the edge computing is capable of alleviating the burden on CPU, having a faster access response, and supporting more flexible AP cooperation.

Frame Structure Design for Vehicular-to-Roadside Unit Communications Using Space–Time Line Code Under Time-Varying Channels

This paper proposes the application of a space-time line code (STLC) scheme to vehicular-to-roadside unit communication systems. For the STLC encoding, channel state information is estimated before the data transmission. Thus, owing to the channel variation, the discrepancy between the estimated and actual channels degrades the communication performance, particularly at the end of the data frame. Considering the time-varying channels, a frame length is designed to maximize the worst-case throughput of the frame end and numerically validated.

Tricopter Vehicle Frame Structure Design Integrated as Platform of Fixed Wing Atha Mapper 2150

To upgrade aerial vehicle of Atha Mapper 2150 capable of vertical take-off and landing capability, it needs to be integrated to the tricopter vehicle. In this study the tricopter frame structure was designed based on the Atha Mapper 2150 fixed wing vehicle. This study began with a calculation process to determine the dimensions of the tricopter.. Next, the process of building four tricopter concept designs with variations of the shape of the frame and the cross section of the arm. The four concept designs are selected using a decision matrix. Based on the values in decision matrix table, the design concept I (Y configuration and rectangular arm cross section) was the best design, because it has the highest weighting value. The selected design was then simulated for its structural strength in Ansys software by giving a load of thrust to the three arms of the tricopter frame. In the middle of frame is given a boundary condition in the form of hinges. From the static simulation results of the tricopter frame structure, the maximum stress value was 54,126 MPa, which occurred on the M3 arm. The greatest total deformation also occurred in the M3 arm with a value of 10,335 mm. The safety factor value of tricopter frame structure was 8.77. This shows the tricopter frame structure with the main material in the form of carbon fiber, acrylic and PLA meets the required safety criteria.

A co-rotational curved beam element for geometrically nonlinear analysis of framed structures

Curved beams are sometimes used in practical framed structures due to good mechanical properties and artistic design. In a framed structure, curved beams may undergo large displacement and experience nonlinear behavior as same as the other straight slender beam-column members. Thus, a geometrically nonlinear curved beam element plays an important role in the analysis of framed structures with curved beams. However, most existing curved beam elements are not accurate enough and still need several or even dozens of elements to accurately describe the behavior of a curved beam with a large subtended angle. To fill this gap, this paper presents a novel geometrically nonlinear curved beam element based on the element-independent co-rotational (EICR) method. The proposed element can simulate a curved beam using only one single element in the analysis and design of most practical framed structures. Moreover, this element is directly derived in a Cartesian coordinate system and can be directly and conveniently used with straight beam-column elements in nonlinear structural analysis. In this manuscript, the derivation of the proposed geometrically nonlinear curved beam element is detailed and several benchmark problems are proposed to verify its accuracy and efficiency.

Architectural and engineering design criteria for earthquake resistant masonry infilled RC frames containing openings

In earthquake resistant design of RC frame structures, the definition of masonry infilled frame is often split between reinforced concrete and the masonry structures. However, it is known that the frame elements and the masonry wall work as a coupled system. Additionally, a dedicate chapter for the definitions of openings size, quantity and position is missing. The definition of a full, partial or non-masonry infilled frame with opening is not establish in engineering and architectural codes; rather, recommendations are given. A competent masonry infilled frame with openings would mean to correlate the architectural and engineering concepts as to define an engineered or non-engineered infilled wall. Likewise, certain boundaries should be established using both the architectural and engineering concepts to relate the importance of illumination and air ventilation product of the openings and masonry infilled frame failure patterns.

The strong column–weak beam design philosophy in reinforced concrete frame structures: A literature review

This article presents a literature review of existing research on the strong column–weak beam design philosophy, which has been widely adopted in the seismic design of frame structures. A comprehensive review of this design philosophy, including its concept and research history, especially factors affecting the accurate calculation of the flexural capacity of beams [Formula: see text] and the determination of the column-to-beam flexural strength ratio [Formula: see text], is presented first. The development of design provisions of four representative countries for this design philosophy is also reviewed. The implementation of strong column–weak beam hierarchy in real structural design is then discussed, and existing problems are pointed out. Finally, different techniques for the seismic retrofit of existing reinforced concrete frames are reviewed.

Experimental Research On Static Strength of C-shaped Steel Structure in Photovoltaic Agricultural Greenhouse

Based on the research characteristics of the C-shaped steel structure of the photovoltaic agricultural greenhouse, the stress and strain under the design load of the solar cell module support are tested. Compared with the ANSYS simulation and test data, the test results are in good agreement with the simulation analysis results. The maximum stress measured by the main steel frame structure under the required load is far less than the steel stress value, the structural safety strength is high, there is a big reduction Heavy margin. The research results can provide a reference for the engineering design of the photovoltaic agricultural greenhouse steel frame structure.

HD video transmission of multi-rotor Unmanned Aerial Vehicle based on 5G cellular communication network

In UAV (Unmanned Aerial Vehicle) mission scenarios for aerial reconnaissance and aerial photography, wireless video backhaul is one of the essential functions. In recent years, with the rapid development of UAV in the military and civilian fields, mobile high-quality video backhaul has become a trend. This paper analyzes the hardware structure and software architecture of the UAV HD video wireless transmission model. The overall model is described from three levels of hardware, software, and link interface, and its software architecture is analyzed. Aiming at the high-frequency and large-bandwidth transmission system under 5G small cells, the influence of new channel characteristics on physical layer parameters is analyzed, and the frame structure design parameters such as subcarrier spacing and cyclic prefix are optimized. Considering the low throughput rate in multi-hop wireless networks, this paper innovatively proposes a slide mode based on frame rate adjustment. The simulation results show that the revised throughput prediction value has higher accuracy than the traditional method, and the bit rate adjustment is timely and can maintain a certain stability. Combining the advantages of the high and low bit rate schemes, the continuous video transmission is maintained while providing higher quality.

Estimation of Cyclic Demand in Metallic Yielding Dampers Installed on Frame Structures

The efficacy of hysteretic dampers can be formulated as the number or equivalent inelastic cycles, or the ratio of normalised dissipated energy to displacement ductility. This parameter is used in the design of framed structures with supplemental dampers and it is strongly influenced by the impulsive effects of earthquakes and other structural parameters. This paper presents an estimate of the cyclic demand of dampers installed in reinforced concrete frames, based on nonlinear time history analyses. Statistical analyses of the results are used to highlight relevant parameters and calibrate a predictive formula and upper-bound design values. The collapse pattern of the frames seems to have no effect on the efficacy of the dampers; thus, the seismological parameters that describe impulsivity should drive the design of hysteric dampers.

Seismic design and assessment of steel-concrete frame structures with welded dissipative fuses

This research presents the design and numerical assessment of composite steel-concrete frame structures with welded dissipative fuses. The assessment has been carried out based on linear response spectrum, nonlinear static pushover and time history procedures. The analytical expressions which define the envelope of the nonlinear response of the dissipative fuses are first presented and calibrated against experimental results available in literature. The assessment is then carried out according to a design methodology proposed herein. Outcomes of the numerical assessment indicate that the use of welded dissipative fuses successfully limited damage within the replaceable parts. Furthermore, although structures with dissipative fuses present lower strength and, generally, lower displacement capacity, their displacement ductility and global dissipative performance are generally higher than conventional structures, especially when the structure with dissipative fuses presents a dissipative configuration adjusted to the bending moment distribution diagram calculated for the applied seismic action.

Optimum Design of Frame Structures From a Stock of Reclaimed Elements

This paper presents optimization methods to design frame structures from a stock of existing elements. These methods are relevant when reusing structural elements over multiple service lives. Reuse has the potential to reduce the environmental impact of building structures because it avoids sourcing new material, it reduces waste and it requires little energy. When reusing elements, cross-section and length availability have a major influence on the structural design. In previous own work, design of truss structures from a stock of elements was formulated as a mixed-integer linear programming (MILP) problem. It was shown that this method produces solutions which are global optima in terms of stock utilization. This work extends previous formulations to stock-constrained optimization of frame structures subject to ultimate and serviceability limit states hence expanding the range of structural typologies that can be designed through reuse. Fundamental to this method is the globally optimal assignment of available stock elements to member positions in the frame structure. Two scenarios are considered: A) the use of individual stock elements for each member of the frame, and B) a cutting stock approach, where multiple members of the frame are cut from a single stock element. Numerical case studies are presented to show the applicability of the proposed method to practical designs. To carry out the case studies, a stock of elements was inventoried from shop drawings of deconstructed buildings. Results show that through reusing structural elements a significant reduction of embodied greenhouse gas emissions could be achieved compared to optimized structures made of new elements.

Simplified model for assessing progressive collapse resistance of reinforced concrete frames under an interior column loss

The key to the research of progressive structural collapse is to perform an in-depth investigation into the structural collapse mechanism at the onset of structural component failure due to accidental events and the demand of progressive collapse resistance for the remaining substructures. According to existing research findings, both beams and floors are important anti-progressive structural collapse components. However, the most common available methods for analyzing progressive collapse adopt the empirical coefficient assumption, which lacks the theoretical basis and neglects the contribution of floor resistance. This assumption leads to discrepancies between design and practice and causes unnecessary construction costs. This paper builds the resistance-deformation theoretical framework for the entire progressive collapse of framed structures under an interior column failure scenario based on yield line theory, where the contribution of floor resistance in the structural collapse is taken into consideration. By comparing experimental results to a finite element model, the simplified models are validated from aspects of both experimental and numerical simulations. To further validate the model, a set of beam-slab progressive collapse tests were designed in accordance with the Code for Design of Concrete Structures. Finally, simplified models accounting for floor resistance in the load-carrying and deformation capacities of RC structures to resist progressive collapse were developed to provide a quantitative estimation for practical applications in the design of frame structures.

Improved genetic algorithm with two-level multipoint approximation for complex frame structural optimization

In this paper, an improved structural topology and sizing optimization method is developed for the fast and efficient engineering design of complex frame structures where beam elements are mainly used in the structures. Discrete and continuous variables are included that the elimination or existence of beam elements are treated as discrete variables (0,1), and the continuous sizing variables of beam cross sections are considered to be continuous variables. To solve the mixed variable problem, the paper introduces a two-level multipoint approximation strategy (TMA). The first-level approximate problem is established by using the branched multipoint approximate function, which includes both two types of variables. Genetic algorithm (GA) is used to determine the absence or presence of beam members. The second-level approximate problem that only involving retained continuous size variables is made on this basis, which uses Taylor expansion and dual methods to solve the inner layer continuous optimization problem. Meanwhile, a strategy of adding a new complementary design point is adopted to expend the search scopes and improve the precision. Temporal deletion techniques are used to temporarily remove redundant constraints and local vibration modes processing techniques are used for continuum topology optimization under frequency constraints. Several representative examples are investigated to validate the effectiveness of the improved method.

Plant Layout Optimization for Chemical Industry Considering Inner Frame Structure Design

Plant layout design is a complex task requiring a wealth of engineering experience. A well-designed layout can extraordinarily reduce various costs, so layout study is of great value. To promote the research depth, plenty of considerations have been taken. However, an actual plant may have several frames and how to distribute facilities and determine the location of them in the different frames has not been well studied. In this work, frames are set as a special kind of inner structure and are added into the model to assign facilities into several blocks. A quantitative method for assigning facilities is proposed to let the number of cross-frame connections be minimized. After allocating the facilities into several blocks, each frame is optimized to obtain initial frame results. With designer decisions and cross-frame flow information, the relative locations of frames are determined and then the internal frame layouts are optimized again to reach the coupling optimization between frame and plant layout. Minimizing the total cost involving investment and operating costs is set to be the objective. In the case study, a plant with 138 facilities and 247 material connections is studied. All the facilities are assigned into four frames, and only 17 connections are left to be cross-frame ones. Through the two optimizations of each frame, the length of cross-frame connections reduces by 582.7 m, and the total cost decreases by 4.7 × 105 ¥/a. Through these steps, the idea of frame is successfully applied and the effectiveness of the proposed methodology is proved.

Assessment and Design of Steel frame Structure, consists Performance of Connection Joints with Tekla & Staad Pro

Steel offer the range of advantages to the structure Industry. The erudition of steel gives architects, and the freedom was to achieve the most ambitious visions. Steel is also one of the most sustainable construction materials, building owners naturally value the flexibility of steel buildings in addition the value of benefits they provide. Steel is ideal for modernization, reconfiguring, extending or adapting with minimal disruption. The conception of design analysis as well as modelling of steel structures is the most up-to-date edition in the civil engineering field. It is necessary to model a steel structure but if it is also analysed during its modelling then there will not be any chances of failure. Tekla structures are powerful and flexible software for all structural projects. Flurry up our construction work with an enormous of standard connections for all structural projects. In construction field, we create a evident, constructible 3D model of any steel structure from everyday industrial and commercial buildings to stadiums and high rise buildings. This project dealing with manual connection designing by using of Standards (ISO, AISC, AWS etc..). As well as considering of OSHA rules. Implemented manual designing and modelling by using of Tekla software. And the connections are an important part of steel structure like beam to column connections, moment connections. And are designed more conventionally than any individual members. The aim of this project work is to analyse a 7-storeyed commercial building for different load combinations using STAAD Pro software. And behaviour of connection of bolts.

Reinforcement learning for optimum design of a plane frame under static loads

A new method is presented for optimum cross-sectional design of planar frame structures combining reinforcement learning (RL) and metaheuristics. The method starts from RL jointly using artificial neural network so that the action taker, or the agent, can choose a proper action on which members to be increased, reduced or kept their size. The size of the neural network is compressed into small numbers of inputs and outputs utilizing story-wise decomposition of the frame. The trained agent is used in the process of generating a neighborhood solution during optimization with simulated annealing (SA) and particle swarm optimization (PSO). Because the proposed method is able to explore the solution space efficiently, better optimal solutions can be found with less computational cost compared with those obtained solely by metaheuristics. Utilization of RL agent also leads to high-quality optimal solutions regardless of variation of parameters of SA and PSO or initial solution. Furthermore, once the agent is trained, it can be applied to optimization of other frames with different numbers of stories and spans.