Design Of Structural Systems Research Articles

Nonlinear technique of prestressing spatial structures

One of the crucial aspects of the design of structural space systems is the degree of prestressing since it is involved in the load transferring, deformability and charges. The prestress state can be reached via required member alteration. This paper presents an efficient nonlinear numerical approach based on the force method for prestressing the spatial nonlinear structures to the desired level through computing nonlinear actuation as a function of external nodal displacements. Two equations are derived for indicating the required amount of member alteration eo and prestressing level by using Taylor's series and Pade approximation methods. This technique can be applied to both rigid and flexible spatial structures. The present technique is validated based on three numerical examples, and the computational findings are in well agreement with the compared methods. The results show that the new approach requires less effort and makes greater economic sense. Moreover, the member forces with concern to nonlinear eo of double-layer space grid structure by imposing lack of fit of some members successfully obtained.

Interval Fuzzy Type-2 Sliding Mode Control Design of Six-DOF Robotic Manipulator

The remarkable features of hybrid SMC assisted with fuzzy systems supplying parameters of the controller have led to significant success of these control approaches, especially in the control of multi-input and multi-output nonlinear systems. The development of type-1 fuzzy systems to type-2 fuzzy systems has improved the performance of fuzzy systems due to the ability to model uncertainties in the expression of expert knowledge. Accordingly, in this paper, the basic approach of designing and implementing the interval type-2 fuzzy sliding mode control was proposed. According to the introduced systematic design procedure, complete optimal design of a type-2 fuzzy system structure was presented in providing sliding mode control parameters by minimizing tracking error and control energy. Based on the proposed method, the need for expert knowledge as the main challenge in designing fuzzy systems was eliminated. In addition, the possibility to limit the control outputs to deal with actuators’ saturation was made available. The control method was implemented on a six-degree-of-freedom robot manipulator that was exposed to severe external disturbances, and its performance was compared to a type-1 fuzzy system as well as to the conventional SMC. The achievements revealed improved performance of the combined control system of fuzzy sliding mode type-2 in comparison with its control counterparts.

Prediction of ultimate conditions and stress–strain behaviour of steel-confined ultra-high-performance concrete using sequential deep feed-forward neural network modelling strategy

Recognising that ultra-high-performance concrete (UHPC) is gaining momentum in structural applications, providing an accurate confinement model is essential to developing a reliable design of UHPC structural members. However, very limited number of models are currently available and these models were empirically formulated and calibrated upon limited test data obtained by the originators of the models. The significant cost associated with comprehensive experimental testing motivates the exploration of cheaper and more efficient data-driven based machine learning approach. This study proposes a sequential artificial neural network (ANN) framework to develop such a data-driven confinement model, incorporating a comprehensive database of 228 axially loaded UHPC columns compiled from available literature. Three deep feed-forward neural network models were established to predict the ultimate stress, ultimate strain and stress–strain behaviour of confined UHPC. The results show that the proposed ANN-based ultimate condition models provide a more robust prediction results compared to the existing design-oriented models for confined UHPC. The stress–strain behaviour, predicted using the proposed ANN model, shows high accuracy levels in capturing different types of stress–strain curves as well as reasonably matching results with those experimentally measured responses. The encouraging outcomes in this study suggest that the proposed models are capable of providing rapid prediction tools that will help to facilitate the on-demand design of UHPC structural components and systems.

Analysis of Thermal Effects in Kilowatt High Power Diamond Raman Lasers

Chemical vapor deposition (CVD) diamond crystal is considered as an ideal material platform for Raman lasers with both high power and good beam quality due to its excellent Raman and thermal characteristics. With the continuous development of CVD diamond crystal growth technology, diamond Raman lasers (DRLs) have shown significant advantages in achieving wavelength expansion with both high beam quality and high-power operation. However, with the output power of DRLs reaching the kilowatt level, the adverse effect of the thermal impact on the beam quality is progressively worsening. Aiming to enunciate the underlying restrictions of the thermal effects for high-power DRLs (e.g., recently reported 1.2 kW), we here establish a thermal-structural coupling model, based on which the influence of the pump power, cavity structure, and crystal size have been systematically studied. The results show that a symmetrical concentric cavity has less thermal impact on the device than an asymmetrical concentric cavity. Under the ideal heat dissipation condition, the highest temperature rise in the diamond crystal is 23.4 K for an output power of ~2.8 kW. The transient simulation further shows that the heating and cooling process of DRLs is almost unaffected by the pump power, and the times to reach a steady state are only 1.5 ms and 2.5 ms, respectively. In addition, it is also found that increasing the curvature radius of the cavity mirror, the length and width of the crystal, or decreasing the thickness of the crystal is beneficial to alleviating the thermal impact of the device. The findings of this work provide some helpful insights into the design of the cavity structure and heat dissipation system of DRLs, which might facilitate their future development towards a higher power.

Design of stainless steel structural systems by GMNIA with strain limits

Design by GMNIA (Geometrically and Materially Nonlinear Analysis with Imperfections) allows the key behavioural features of structures to be directly captured in the analysis, improving accuracy and dramatically reducing the need for subsequent design checks. Since the analysis of frames typically employs beam elements, in which local buckling of cross-sections cannot be explicitly simulated, cross-section classification and capacity checks remain necessary. However, the step-wise and overly conservative nature of these traditional checks restricts accuracy. To resolve this, the use of strain limits, defined using the Continuous Strength Method, in place of these cross-section checks has been proposed. This design method is extended to indeterminate stainless steel structural systems herein. Ultimate load-carrying capacity predictions from the proposed design approach are compared against results obtained from benchmark shell finite element models as well as predictions using traditional stainless steel design methods. The new design framework allows for element interaction at the cross-section level, the influence of local moment gradients, the partial spread of plasticity, moment redistribution, strain hardening and the visualisation of the structural failure mechanism, resulting in more accurate and consistent resistance predictions. The method is included in AISC 370 and prEN 1993-1-14 offering a step change in efficiency for the future direction of structural stainless steel design.

Reliable Design and Control Implementation of Parallel DC/DC Converter for High Power Charging System

With the current popularity of Electric Vehicles (EV), especially in some critical EV applications such as hospital EV fleets, the demand for continuous and reliable power supply is increasing. However, most of the charging stations are powered in a centralized way, which causes transistors and other components to be subjected to high voltage and current stresses that reduce reliability, and a single point of failure can cause the entire system to fail. Therefore, a significant effort is made in this paper to improve the reliability of the charging system. In terms of charging system structure design, a distributed charging structure with fault tolerance is designed and a mathematical model to evaluate the reliability of the structure is proposed. In terms of control, a current sharing control algorithm is designed that can achieve fault tolerance. To further improve the reliability of the system, a thermal sharing control method based on current sharing technology is also designed. This method can improve the reliability of the charging system by distributing the load more rationally according to the differences in component performance and operating environment; FPGA-based control techniques are provided, and innovative ideas of pipeline control and details of mathematical reasoning for key IP cores are presented. Experiments show that N + 1 redundancy fault tolerance can be achieved in both current sharing and thermal sharing modes. In the current sharing experiment, when module 3 failed, the total current only fluctuated 800 mA within 500 ms, which is satisfactory. In the thermal sharing experiment, after module 3 failed, modules 1, 2, and 4 adjusted the current reasonably under the correction of the thermal sharing loop, and the total current remained stable throughout the process. The experimental results prove that the charging system structure design and control method proposed in this paper are feasible and excellent.

Design of Flue Gas Eliminating White Monitoring System for Natural Gas Boiler

Aiming at the phenomenon that the flue gas discharged from a heating boiler contains waste heat and harmful gas, which causes energy waste and air pollution, the flue gas eliminating white monitor system based on Programmable Logic Controller (PLC) and MCGS configuration technology is designed. The system structure design is introduced, including the system hardware design, software design, monitoring screen design, and debugging of the physical system. In view of the problem that the waste heat of 45 °C still exists in the flue gas after being treated by the primary heat exchanger, the compressor is used to cool the gas to below 10 °C, which establishes the working conditions of flue gas eliminating white. The experimental results show that the system can control the start and stop of the compressor and the flue gas outlet temperature. The flue gas outlet temperature drops rapidly from about 40 °C to about 8 °C within about 10 minutes and reaches stability. The design of the system not only reduces the air thermal pollution but also establishes the basic conditions for flue gas eliminating white.

Enterprise Architecture Design Using The Open Group Architecture Framework (TOGAF) at Logistic Courier Services

Logistics services are growing day by day in line with increasing consumer demand. This supports a new habit, namely express service delivery activities. All these delivery service activities require a structured system design so that users can use various kinds of logistics services. The role of enterprise architecture planning that can provide a framework as a reference for developing information systems, namely TOGAF (Open Group Architecture Framework). Through this research, it is hoped that the company can improve the effectiveness and efficiency of work in its business processes and integrate company systems that can support the company's business processes. Therefore, in this article, we will conduct an Enterprise Architecture Design Using the Open Group Architecture Framework (TOGAF) at Logistic Courier Services (LCS) Indonesia to identify problems. In the system, a blueprint is needed, because enterprise architecture planning can provide a framework as a reference for developing information systems. Through this article, LCS does not have serious problems in the system so that users do not feel so disturbed when using this logistics delivery service. However, there are still some things that must be improved and maintained to reduce errors when using this shipping service.

Inconsistency evaluation of vehicle-oriented fuel cell stacks based on electrochemical impedance under dynamic operating conditions

The dynamic inconsistency performance of the proton exchange membrane fuel cell stack is a crucial indicator for vehicular applications. This paper comprehensively studies for the first time the local dynamic inconsistency of a high-power fuel cell stack with 30 kW rated power based on impedance. The stack is divided into ten groups equally. First, each polarization process and frequency impedance under different working conditions is quantitatively analyzed by the equivalent circuit model combined with the relaxation time distribution. It is determined that 1 Hz, 50 Hz, and 2500 Hz impedance can describe the oxygen transport, charge transfer, and ohmic variation trends, respectively. Then, the effects of loads, air stoichiometry, backpressure, operating temperature, and cathode humidity on in-stack dynamic inconsistency response are evaluated from an internal dynamics perspective. The results show that the local dynamic inconsistent responses in the fuel cell stack depend mainly on the oxygen transfer capacity. Oxygen transport affects the difference in local voltage transient drop after a current step and the inconsistency voltage recovery. These works provide an in-depth understanding of the differences in the dynamic response of high-power fuel cell stacks, which has an important implication for system control and structural design optimization.

Structural system design and earthquake response analysis of prefabricated pile-plate bridge

ABSTRACT With the advancement of building technology, the pile-plate structure, which originated in railway engineering, has been adopted into highway engineering. This study presents a new pile-plate structure connecting node. The addition of energy-dissipating components at the nodes and the use of non-shrinkage concrete at the joints demonstrate its novelty. The node’s ability to enter the plastic stage is enhanced, resulting in increased seismic performance. In this study, the seismic performance and energy consumption capacity of the pile plate joint were studied by numerical model, and the results showed that the stagnation curve of the pipe pile under low cycle reciprocating load was full and had good energy consumption capacity. Under the action of random seismic vibration, the displacement of the pile plate structure in one direction is up to 0.023 m, which meets the requirements of the specification. The innovative pile-plate joints are used in a nonlinear dynamic time-history analysis of the constructed bridge structure.

High-Misalignment Tolerance Wireless Charging System for Constant Power Output Using Dual Transmission Channels With Magnetic Flux Controlled Inductors

Although the wireless charging system (WCS) achieves flexible power transmission, high system operating performance needs strong anti-misalignment capability and excellent charging controllability. Hence, this article proposes a mistuned WCS that features dual transmission channels using half-bridge inverters, magnetic flux controlled inductors (MFCIs), magnetic couplers with hybrid coils (HMCs), and the series–series compensation. Then, high misalignment tolerance and high-efficient constant power (CP) charging are achieved. First, the interrelation among the mutual inductance, adjustable inductance, load resistance, charging power, and system efficiency is analyzed based on the optimally designed system structure. Second, the circuit structure and working principle of the MFCI are illustrated. Third, the anti-misalignment capability of the optimized HMC is verified by analyzing its coupling characteristics. Then, the relative spatial position between the two HMCs is determined to ensure the negligible cross-coupling influence. In addition, the closed-loop controller's working principle and design method is analyzed to achieve high-efficient and high-controllable CP charging within a wide range of misalignment distance and load resistance. Finally, the experimental results validate the feasibility of the proposed WCS. For CP charging of 150 W, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -direction misalignment ranges reach ±95% and ±47%, and system efficiency exceeds 90%, superior to the commonly used anti-misalignment methods.

Economically Prudent Design (EPC) of Outrigger-Based Structural Systems

As the construction of mega-tall buildings in all major cities around the world accelerates, the seismic risk associated with them also rises. Hence study on the response of tall buildings to earthquake loads is gaining significant importance. Outrigger tall buildings are one of the most common structural structures because they are simple to construct, cost-effective, and have significant lateral stiffness. Therefore, this research explores a structural outrigger system for high-rise buildings to analyze the output of a system by changing the place of outrigger positions. Dynamic research was performed in accordance with IS 1893, the response spectrum and time of California’s most recent earthquakes. The parameters discussed are lateral displacements, inter-storey drifts for static analysis, and base force, displacement, and spectral acceleration for dynamic analysis. From the analyzed results, it was found that an outrigger when located at H0/H=0.6 causes a maximum reduction in the lateral displacement. Hence outrigger located at H0/H=0.6 is the desired location to provide an outrigger in a structural system and could act as an initial economical prudent design solution in the construction of tall buildings with outriggers. Time history analysis shows that the reduction is maximum when the outrigger is located at H0/H=0.9 for LA03, H0/H=0.85 for LA06 H0/H=1.0 for LA14.

Design and Implementation of a Web-Based Lecturers’ Evaluation System (A Case Study of Computer Science Department, Isa Mustapha Agwai I Polytechnic, IMAP, Lafia)

The study focused on design and implementation of a web-based lecturer evaluation system. To accomplish this, the structured system analysis and design methodology (SSDAM) was adopted. The software development tools used were PhP, CSS5, HTML, and MYSQL. The application has the Admin, Student and Lecturer modules. The admin manages students, courses, evaluation questions and criteria. The student module manages students’ ratings of their lecturers while the lecturer module manages lecturers and enables a lecturer to view his mean rating report at the end of a semester.

Wind-resistant structural optimization of irregular tall building using CFD and improved genetic algorithm for sustainable and cost-effective design

Tall buildings with irregular shapes and considerable heights are gaining popularity in creating the vertical cities around the world. They also considered one of the major energy consumers with little regards to sustainability. Tall building is wind-sensitive structure and shape plays major role in determining wind loads, which usually govern the design of its lateral resisting system. Thus, evaluating wind loads properly and designing an optimal lateral system accordingly are the main challenges attributed to the design process of irregular tall building. This paper presents a computational procedure for the optimal design of wind-resistant irregular tall building to minimize the total weight of structure within design requirements in single digital environment. That is achieved firstly by creating a digital system of computational fluid dynamic (CFD) analysis that is coupled with pressure-load translation (PLT) algorithm to evaluate the wind motions on irregular tall buildings and generate the design wind loads accordingly. Genetic Algorithm (GA) with enhance design constrains function of lateral displacements, inter-story drifts and top acceleration is then developed to perform structural optimization. A numerical example using 70-story twisting reinforced concrete building is implemented to verify the feasibility of the developed computational procedures. Steady and incompressible flow applied at (0°) angle of attack was implemented in the CFD model to simulate the wind flow on the studied building. Genetic algorithm with improved design constraints of static and dynamic design requirements was developed to optimize the structure effectively and efficiently. The numerical example demonstrates its effectiveness by achieving 35.71% reduction of concrete volume from the original lateral structural system design. This is also translated into a sustainability value by lessening the embedded carbon dioxide by 4,400 tons.

Architectural And Structural System Design of Precast Concrete Structures In Earthquake Zones

Precast concrete systems, which are the result of industrialization in the field of construction, are faced with the prejudice of insufficient earthquake resistance despite their many advantages and their use is limited in Turkey. These systems, which have proven earthquake resistance if they are designed properly, can be used safely in low-rise or multi-storey buildings with different functions in earthquake zones. The aim of this study is to determine the architectural design requirements of earthquake-resistant precast concrete structures and to reveal the structural system design approaches. In accordance with this aim, the earthquake effect on the structures was summarized and architectural design principles that would contribute to the earthquake resistance of precast concrete structures were determined firstly. Then, earthquake-resistant structural system design approaches of frame, panel, and cell construction were evaluated separately.&#x0D;

Design space exploration and decision‐making for a segmented ultralight morphing 50‐MW wind turbine

AbstractWind turbine design encompasses many different aspects including aerodynamic, structural, electrical, and control system design. To achieve optimal plant performance, a system design approach is utilized in which the performance of the whole wind turbine is evaluated and quantified during operational scenarios with subsystem interactions. In this paper, the design for a Segmented Ultralight Morphing Rotor (SUMR) 50‐MW wind turbine is presented utilizing levelized cost of energy (LCOE) for design choices, with additional quantification of simulated performance shortcomings at the 50‐MW scale. The multi‐disciplinary design process results in a final ultra‐scale turbine configuration that outperforms other existing offshore wind farms regarding the LCOE.

Structural Design of Handicrafts Based on Dynamic Simulation Technology

In order to improve the effect of handicraft structure design, this study combines the dynamic simulation technology to build a handicraft structure design system and transmits data through dynamic simulation signals to improve the effectiveness of the interactive design of artworks. In order to provide a simpler and faster development process for interactive media applications, this study develops an interactive media art design system with a node-based visual programming model as the core processing logic. The digital Gaussian shaping method based on the programmable logic device can not only realize real-time Gaussian shaping of the nuclear pulse signal but also meet the needs of later function expansion, maintenance, and upgrade of the system. In addition, this study verifies the effectiveness of the handicraft structure design system based on dynamic simulation technology through the analysis of multiple sets of simulation data.

African vultures optimization algorithm for optimization of shell and tube heat exchangers

Abstract Nature-inspired optimization algorithms named meta-heuristics are found to be versatile in engineering design fields. Their adaptability is also used in various areas of the Internet of things, structural design, and thermal system design. With the very rapid progress in industrial modernization, waste heat recovery from the power generating and thermal engineering organization is an imperative key point to reduce the emission and support the government norms. However, the heat exchanger is the component applied in various heat recovery processes. Out of the available designs, shell and tube heat exchangers (SHTHEs) are the most commonly adopted for the heat recovery process. Hence, cost minimization is the major aspect while designing the heat exchanger confirming various constraints and optimized design variables. In this study, cost minimization of the SHTHE is performed by applying a novel metaheuristic algorithm which is the African vultures optimization algorithm (AVOA). Adopting the AVOA for the best-optimized value (least cost of heat exchanger) and the design parameters are realized, confirming all the constraints. It was found that the AVOA is able to pursue the best results among the rest of them and can be used for the cost optimization of the plate-fin and tube-fin heat exchanger case studies.

Application of Cheerleading Referee Information Management System Based on Data Mining.

In recent years, China has focused on the development of sports and adopted modern, scientific, and standardized management of referees. Global sports events are becoming increasingly fierce. One of the main links is to manage the referee group and ensure the fairness and impartiality of sports competitions. In sports competition, referees implement sports rules, so the quality of referees directly determines whether sports events are fair and just. Cheerleading operation was introduced into China as a new sports event and spread rapidly in major universities and primary and secondary schools. With the increase of the number of cheerleading athletes, the number of referees also continues to increase. Referees' information management has become the main problem. Therefore, this paper uses data mining technology to design and develop cheerleading referee information management system, uses the system to manage the basic information of cheerleading referees, and analyzes the sanction ability and strength of cheerleading referees. This paper first introduces the basic concept and operational process of data mining algorithm, and C4.5 decision tree algorithm, and support vector machine algorithm. Based on this algorithm, a cheerleading referee information management system is established. Then, we analyze the system structure and demand analysis and design the main structure of the system. Finally, the number of cheerleading referees is analyzed. The highest proportion of referees is 29.5%, the number of referees is 3 to 5 times, and the highest proportion of referees with more than 10 times per year is 59.24%. Using this system to analyze the strength of cheerleading referees, the most influential factor is the lack of on-the-spot experience, accounting for 38.83%.

Development and Analysis of a New Cylindrical Lithium-Ion Battery Thermal Management System

With the development of modern technology and economy, environmental protection and sustainable development have become the focus of global attention. The promotion and development of electric vehicles (EVs) have bright prospects. However, many challenges need to be faced seriously. Under different operating conditions, various safety problems of electric vehicles emerge one after another, especially the hidden danger of battery overheating which threatens the performance of electric vehicles. This paper aims to design and optimize a new indirect liquid cooling system for cylindrical lithium-ion batteries. Various design schemes for different cooling channel structures and cooling liquid inlet directions are proposed, and the corresponding solid-fluid coupling model is established. COMSOL Multiphysics simulation software is adopted to simulate and analyze the cooling systems. An approximate model is constructed using the Kriging method, which is considered to optimize the battery cooling system and improve the optimization results. Sensitivity parameter analysis and the optimization design of system structure are performed through a set of influencing factors in the battery thermal management. The results indicate that the method used in this paper can effectively reduce the maximum core temperature and balance the temperature differences of the battery pack. Compared with the original design, the optimized design, which is based on the non-dominated sorting genetic algorithm (NSGA-II), has an excellent ability in the optimized thermal management system to dissipate thermal energy and keep the overall cooling uniformity of the battery and thermal management system. Furthermore, the optimized system can also prevent thermal runaway propagation under thermal abuse conditions. In summary, this research can provide some practical suggestions and ideas for the engineering and production applications and structural optimization design carried by electric vehicles.