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Influence of damages on static behavior of single-layer cable net supported glass curtain wall: full-scale

Gang SHI, Yongjiu SHI, Yuanqing WANG, Yongzhi ZUO, Xiaohao SHI, Zaoyang GUO,

《结构与土木工程前沿（英文）》 2010年 第4卷 第3期   页码 383-395 doi: 10.1007/s11709-010-0074-6

摘要： The single-layer cable net supported glass curtain wall has been applied in many building structures all over the world. In service, it will inevitably be subject to various damages. To study the influence of such damages on the static behavior of the single-layer cable net supported glass curtain wall, a full-scale model with the outside outline size of 4.85 m × 4.85 m and 4 × 4 grids is designed and tested. Two kinds of damages that are the cable prestress loss and cable anchorage end failure are led into the structure model during the test, and their influence has been investigated. The stiffness contribution of glass panels to the single-layer cable net supported glass curtain wall structure with or without damages and its change have been tested and analyzed. The results show that the maximum change rate of nodal deflection is 13.78% for the damage of cable prestress loss, while the change rate of nodal deflection is between 7% and 22% for the damage of cable anchorage end failure. The influence degree of the damages depends on the ratio of the structure initial stress stiffness change caused by damages to the total stiffness of the structure. The stiffness contribution of glass panels increases with the load increase. Under the same loading condition, the stiffness contribution of glass panels to the damaged structure is greater than that to the intact structure. The stiffness contribution of glass panels reduces the effect of the damages on the structural displacement and the cable tension force, but the glass panel could break if its stiffness contribution is too large.

关键词： single-layer plane cable net supported glass curtain wall     damage     cable prestress loss     cable anchorage end failure     stiffness contribution of glass panels    

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国外光纤光纤带和带状光缆技术的最新发展

刘良炎

《中国工程科学》 2001年 第3卷 第9期   页码 86-94

摘要：

综合介绍了近年国外关于低衰耗的色散补偿光纤，非零色散位移光纤，用于恶劣环境的碳涂覆和氮化硅涂覆光纤的研究；光纤带制造技术包括光纤带的结构、涂层、性能、生产工艺，大芯数光纤带状光缆包括层绞式松管、中心松管式、骨架式、干缆芯带状光缆的设计制造技术的最新进展。

关键词： 光纤通信     低衰耗光纤     光纤带     光纤带状光缆    

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Secondary transfer length and residual prestress of fractured strand in post-tensioned concrete beams

Lizhao DAI; Wengang XU; Lei WANG; Shanchang YI; Wen CHEN

《结构与土木工程前沿（英文）》 2022年 第16卷 第3期   页码 388-400 doi: 10.1007/s11709-022-0809-1

摘要： An experimental study is performed on five post-tensioned concrete beams to explore the effects of different fracture positions on secondary transfer length and residual prestress of fractured strand. A numerical model is developed and used to predict the secondary transfer length and residual prestress of fractured strand in post-tensioned concrete beams. The model change interaction, which can deactivate and reactivate the elements for simulating the removal and reproduction of parts of the model, is used to reproduce the secondary anchorage of fractured strand. The numerical model is verified by experimental results. Results shows that the fractured strand can be re-anchored in concrete through the secondary anchorage, and the secondary transfer length of fractured strand with the diameter of 15.2 mm is 1133 mm. The residual prestress of fractured strand increases gradually in the secondary transfer length, and tends to be a constant beyond it. When the fractured strand is fully anchored in concrete, a minor prestress loss will appear, and the average prestress loss is 2.28% in the present study.

关键词： post-tensioned concrete beams     strand fracture     secondary transfer length     residual prestress    

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Finite element modeling of cable sliding and its effect on dynamic response of cable-supported truss

Yujie YU, Zhihua CHEN, Renzhang YAN

《结构与土木工程前沿（英文）》 2019年 第13卷 第5期   页码 1227-1242 doi: 10.1007/s11709-019-0551-5

摘要： The cable system of cable-supported structures usually bears high tension forces, and clip joints may fail to resist cable sliding in cases of earthquake excitations or sudden cable breaks. A analytical method that considers the dynamic cable sliding effect is proposed in this paper. Cable sliding behaviors and the resultant dynamic responses are solved by combining the vector form intrinsic finite element framework with cable force redistribution calculations that consider joint frictions. The cable sliding effect and the frictional tension loss are solved with the original length method that uses cable length and the original length relations. Then, the balanced tension distributions are calculated after frictional sliding. The proposed analytical method is achieved within MATLAB and applied to simulate the dynamic response of a cable-supported plane truss under seismic excitation and sudden cable break. During seismic excitations, the cable sliding behavior in the cable-supported truss have an averaging effect on the oscillation magnitudes, but it also magnifies the internal force response in the upper truss structure. The slidable cable joints can greatly reduce the ability of a cable system to resist sudden cable breaks, while strong friction resistances at the cable-strut joints can help retain internal forces.

关键词： sliding cable     explicit solution framework     original length method     seismic response     cable rupture    

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Panoramic variation analysis of a family with neurodevelopmental disorders caused by biallelic loss-of-function

《医学前沿（英文）》 doi: 10.1007/s11684-023-1006-x

摘要： Highly clinical and genetic heterogeneity of neurodevelopmental disorders presents a major challenge in clinical genetics and medicine. Panoramic variation analysis is imperative to analyze the disease phenotypes resulting from multilocus genomic variation. Here, a Pakistani family with parental consanguinity was presented, characterized with severe intellectual disability (ID), spastic paraplegia, and deafness. Homozygosity mapping, integrated single nucleotide polymorphism (SNP) array, whole-exome sequencing, and whole-genome sequencing were performed, and homozygous variants in TMEM141 (c.270G>A, p.Trp90*), DDHD2 (c.411+767_c.1249-327del), and LHFPL5 (c.250delC, p.Leu84*) were identified. A Tmem141p.Trp90*/p.Trp90* mouse model was generated. Behavioral studies showed impairments in learning ability and motor coordination. Brain slice electrophysiology and Golgi staining demonstrated deficient synaptic plasticity in hippocampal neurons and abnormal dendritic branching in cerebellar Purkinje cells. Transmission electron microscopy showed abnormal mitochondrial morphology. Furthermore, studies on a human in vitro neuronal model (SH-SY5Y cells) with stable shRNA-mediated knockdown of TMEM141 showed deleterious effect on bioenergetic function, possibly explaining the pathogenesis of replicated phenotypes in the cross-species mouse model. Conclusively, panoramic variation analysis revealed that multilocus genomic variations of TMEM141, DDHD2, and LHFPL5 together caused variable phenotypes in patient. Notably, the biallelic loss-of-function variants of TMEM141 were responsible for syndromic ID.

关键词： neurodevelopmental disorder     autosomal recessive intellectual disability     consanguinity     spastic paraplegia     hearing loss     TMEM141    

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Analytical dynamic solution of a flexible cable-suspended manipulator

Mahdi BAMDAD

《机械工程前沿（英文）》 2013年 第8卷 第4期   页码 350-359 doi: 10.1007/s11465-013-0271-9

摘要：

Cable-suspended manipulators are used in large scale applications with, heavy in weight and long in span cables. It seems impractical to maintain cable assumptions of smaller robots for large scale manipulators. The interactions among the cables, platforms and actuators can fully evaluate the coupled dynamic analysis. The structural flexibility of the cables becomes more pronounced in large manipulators. In this paper, an analytic solution is provided to solve cable vibration. Also, a closed form solution can be adopted to improve the dynamic response to flexibility. The output is provided by the optimal torque generation subject to the actuator limitations in a mechatronic sense. Finally, the performance of the proposed algorithm is examined through simulations.

关键词： parallel robot     flexible cable     suspended robot     dynamic    

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State-of-the-art on theories and applications of cable-driven parallel robots

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0693-3

摘要： Cable-driven parallel robot (CDPR) is a type of high-performance robot that integrates cable-driven kinematic chains and parallel mechanism theory. It inherits the high dynamics and heavy load capacities of the parallel mechanism and significantly improves the workspace, cost and energy efficiency simultaneously. As a result, CDPRs have had irreplaceable roles in industrial and technological fields, such as astronomy, aerospace, logistics, simulators, and rehabilitation. CDPRs follow the cutting-edge trend of rigid–flexible fusion, reflect advanced lightweight design concepts, and have become a frontier topic in robotics research. This paper summarizes the kernel theories and developments of CDPRs, covering configuration design, cable-force distribution, workspace and stiffness, performance evaluation, optimization, and motion control. Kinematic modeling, workspace analysis, and cable-force solution are illustrated. Stiffness and dynamic modeling methods are discussed. To further promote the development, researchers should strengthen the investigation in configuration innovation, rapid calculation of workspace, performance evaluation, stiffness control, and rigid–flexible coupling dynamics. In addition, engineering problems such as cable materials, reliability design, and a unified control framework require attention.

关键词： cable-driven parallel robot     kinematics     optimization     dynamics     control    

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Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 321-332 doi: 10.1007/s11465-017-0434-1

摘要：

The magnitude and stability of power output are two key indices of wind turbines. This study investigates the effects of wind shear and tower shadow on power output in terms of power fluctuation and power loss to estimate the capacity and quality of the power generated by a wind turbine. First, wind speed models, particularly the wind shear model and the tower shadow model, are described in detail. The widely accepted tower shadow model is modified in view of the cone-shaped towers of modern large-scale wind turbines. Power fluctuation and power loss due to wind shear and tower shadow are analyzed by performing theoretical calculations and case analysis within the framework of a modified version of blade element momentum theory. Results indicate that power fluctuation is mainly caused by tower shadow, whereas power loss is primarily induced by wind shear. Under steady wind conditions, power loss can be divided into wind farm loss and rotor loss. Wind farm loss is constant at 3α(3α−1)R2/(8H2). By contrast, rotor loss is strongly influenced by the wind turbine control strategies and wind speed. That is, when the wind speed is measured in a region where a variable-speed controller works, the rotor loss stabilizes around zero, but when the wind speed is measured in a region where the blade pitch controller works, the rotor loss increases as the wind speed intensifies. The results of this study can serve as a reference for accurate power estimation and strategy development to mitigate the fluctuations in aerodynamic loads and power output due to wind shear and tower shadow.

关键词： wind turbine     wind shear     tower shadow     power fluctuation     power loss    

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Turnover and loss of nitrogenous compounds during composting of food wastes

YANG Yanmei, ZHANG Xiangfeng, YANG Zhifeng, XI Beidou, LIU Hongliang

《环境科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 251-256 doi: 10.1007/s11783-008-0042-8

摘要： Few people have so far explored into the research of the dynamics of various nitrogenous compounds (including water-soluble nitrogen) in composting of food wastes. This study aimed to investigate the solid-phase nitrogen, water-soluble nitrogen, nitrogen loss together with ammonia volatilization in the process of food wastes composting. A laboratory scale static aerobic reactor in the experiment was employed in the composting process of a synthetic food waste, in which sawdust was used as the litter amendment. In the experiment, oxygen was supplied by continuous forced ventilation for 15 days. The results have shown that the concentrations of total nitrogen and organic nitrogen decrease significantly in the composting process, whereas NH-N concentration increases together with little fluctuation in NO-N. After composting, the total content of the water-soluble nitrogen compounds in the compost greatly increased, the total nitrogen loss amounted to 50% of the initial nitrogen, mainly attributed to ammonia volatilization. 56.7% of the total ammonia volatilization occurred in the middle and late composting of the thermophilic stage. This suggested that the control at the middle and late composting of thermophilic stage is the key to nitrogen loss in the food waste compost.
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Development of a masticatory robot using a novel cable-driven linear actuator with bidirectional motion

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0687-1

摘要： Masticatory robots are an effective in vitro performance testing device for dental material and mandibular prostheses. A cable-driven linear actuator (CDLA) capable of bidirectional motion is proposed in this study to design a masticatory robot that can achieve increasingly human-like chewing motion. The CDLA presents remarkable advantages, such as lightweight and high stiffness structure, in using cable amplification and pulley systems. This work also exploits the proposed CDLA and designs a masticatory robot called Southeast University masticatory robot (SMAR) to solve existing problems, such as bulky driving linkage and position change of the muscle’s origin. Stiffness analysis and performance experiment validate the CDLA’s efficiency, with its stiffness reaching 1379.6 N/mm (number of cable parts n = 4), which is 21.4 times the input wire stiffness. Accordingly, the CDLA’s force transmission efficiencies in two directions are 84.5% and 85.9%. Chewing experiments are carried out on the developed masticatory robot to verify whether the CDLA can help SMAR achieve a natural human-like chewing motion and sufficient chewing forces for potential applications in performance tests of dental materials or prostheses.

关键词： masticatory robot     cable-driven     linear actuator     parallel robot     stiffness analysis    

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Nonlinear analysis of cable structures using the dynamic relaxation method

Mohammad REZAIEE-PAJAND, Mohammad MOHAMMADI-KHATAMI

《结构与土木工程前沿（英文）》 2021年 第15卷 第1期   页码 253-274 doi: 10.1007/s11709-020-0639-y

摘要： The analysis of cable structures is one of the most challenging problems for civil and mechanical engineers. Because they have highly nonlinear behavior, it is difficult to find solutions to these problems. Thus far, different assumptions and methods have been proposed to solve such structures. The dynamic relaxation method (DRM) is an explicit procedure for analyzing these types of structures. To utilize this scheme, investigators have suggested various stiffness matrices for a cable element. In this study, the efficiency and suitability of six well-known proposed matrices are assessed using the DRM. To achieve this goal, 16 numerical examples and two criteria, namely, the number of iterations and the analysis time, are employed. Based on a comprehensive comparison, the methods are ranked according to the two criteria. The numerical findings clearly reveal the best techniques. Moreover, a variety of benchmark problems are suggested by the authors for future studies of cable structures.

关键词： nonlinear analysis     cable structure     stiffness matrix     dynamic relaxation method    

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Winner determination problem with loss-averse buyers in reverse auctions

Xiaohu QIAN, Min HUANG, Yangyang YU, Xingwei WANG

《工程管理前沿（英文）》 2017年 第4卷 第2期   页码 212-220 doi: 10.15302/J-FEM-2017019

摘要： Reverse auctions have been widely adopted for purchasing goods and services. This paper considers a novel winner determination problem in a multiple-object reverse auction in which the buyer involves loss-averse behavior due to uncertain attributes. A corresponding winner determination model based on cumulative prospect theory is proposed. Due to the NP-hard characteristic, a loaded route strategy is proposed to ensure the feasibility of the model. Then, an improved ant colony algorithm that consists of a dynamic transition strategy and a Max-Min pheromone strategy is designed. Numerical experiments are conducted to illustrate the effectiveness of the proposed model and algorithm. We find that under the loaded route strategy, the improved ant colony algorithm performs better than the basic ant colony algorithm. In addition, the proposed model can effectively characterize the buyer’s loss-averse behavior.

关键词： reverse auction     loss aversion     winner determination     improved ant colony algorithm    

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A modular cable-driven humanoid arm with anti-parallelogram mechanisms and Bowden cables

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0722-2

摘要： This paper proposes a novel modular cable-driven humanoid arm with anti-parallelogram mechanisms (APMs) and Bowden cables. The lightweight arm realizes the advantage of joint independence and the rational layout of the driving units on the base. First, this paper analyzes the kinematic performance of the APM and uses the rolling motion between two ellipses to approximate a pure-circular-rolling motion. Then, a novel type of one-degree-of-freedom (1-DOF) elbow joint is proposed based on this principle, which is also applied to design the 3-DOF wrist and shoulder joints. Next, Bowden cables are used to connect the joints and their driving units to obtain a modular cable-driven arm with excellent joint independence. After that, both the forward and inverse kinematics of the entire arm are analyzed. Last, a humanoid arm prototype was developed, and the assembly velocity, joint motion performance, joint stiffness, load carrying, typical humanoid arm movements, and repeatability were tested to verify the arm performance.

关键词： modular robotic arm     anti-parallelogram mechanism     Bowden cable     humanoid arm     lightweight joint design    

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A novel energy loss model and optimization design of the coin chute flection curve

Qinghua LIANG, Jinqiu MO, Weizhong GUO

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 38-46 doi: 10.1007/s11465-012-0311-x

摘要：

In this paper, we propose a novel design model based on the energy loss of the coin (ELM model) to optimize the flection curve, which is widely used in coin operated machines. Two different kinds of energy loss models are analyzed according to dynamic characteristics of the coin falling movement. The flection curve is constructed based on cubic quasi-uniform B-spline with the data points and end points derivatives as inputs, and the curve model is governed and affected by energy loss equations, allowing to minimize the total energy loss before the coin arrives at the detecting position, thus to reduce the energy loss and collisions between the coin and the flection, thus to improve the testing accuracy. A case study with a typical Chinese currency coin shows the effectiveness of the model using GA optimization toolbox.

关键词： flection curve     B-spline     energy loss model (ELM model)     optimization design    

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Deflection behavior of a prestressed concrete beam reinforced with carbon fibers at elevated temperatures

Mohammed FARUQI, Mohammed Sheroz KHAN

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 81-91 doi: 10.1007/s11709-018-0468-4

摘要： Fiber reinforced polymer(FRP) have unique advantages like high strength to weight ratio, excellent corrosion resistance, improving deformability and cost effectiveness. These advantages have gained wide acceptance in civil engineering applications. FRP tendons for prestressing applications are emerging as one of the most promising technologies in the civil engineering industry. However, the behavior of such members under the influence of elevated temperatures is still unknown. The knowledge and application of this could lead to a cost effective and practical considerations in fire safety design. Therefore, this study examines the deflection behavior of the carbon fiber reinforced polymer(CFRP) prestressed concrete beam at elevated temperatures. In this article, an analytical model is developed which integrates the temperature dependent changes of effective modulus of FRP in predicting the deflection behavior of CFRP prestressed concrete beams within the range of practical temperatures. This model is compared with a finite element mode (FEM) of a simply supported concrete beam prestressed with CFRP subjected to practical elevated temperatures. In addition, comparison is also made with an indirect reference to the real behavior of the material. The results of the model correlated reasonably with the finite element model and the real behavior. Finally, a practical application is provided.

关键词： FRP     CFRP     concrete     elevated temperatures     deflections     prestress    

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标题 作者 时间 类型 操作

Influence of damages on static behavior of single-layer cable net supported glass curtain wall: full-scale

Gang SHI, Yongjiu SHI, Yuanqing WANG, Yongzhi ZUO, Xiaohao SHI, Zaoyang GUO,

期刊论文

国外光纤光纤带和带状光缆技术的最新发展

刘良炎

期刊论文

Secondary transfer length and residual prestress of fractured strand in post-tensioned concrete beams

Lizhao DAI; Wengang XU; Lei WANG; Shanchang YI; Wen CHEN

期刊论文

Finite element modeling of cable sliding and its effect on dynamic response of cable-supported truss

Yujie YU, Zhihua CHEN, Renzhang YAN

期刊论文

Panoramic variation analysis of a family with neurodevelopmental disorders caused by biallelic loss-of-function

期刊论文

Analytical dynamic solution of a flexible cable-suspended manipulator

Mahdi BAMDAD

期刊论文

State-of-the-art on theories and applications of cable-driven parallel robots

期刊论文

Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

期刊论文

Turnover and loss of nitrogenous compounds during composting of food wastes

YANG Yanmei, ZHANG Xiangfeng, YANG Zhifeng, XI Beidou, LIU Hongliang

期刊论文

Development of a masticatory robot using a novel cable-driven linear actuator with bidirectional motion

期刊论文

Nonlinear analysis of cable structures using the dynamic relaxation method

Mohammad REZAIEE-PAJAND, Mohammad MOHAMMADI-KHATAMI

期刊论文

Winner determination problem with loss-averse buyers in reverse auctions

Xiaohu QIAN, Min HUANG, Yangyang YU, Xingwei WANG

期刊论文

A modular cable-driven humanoid arm with anti-parallelogram mechanisms and Bowden cables

期刊论文

A novel energy loss model and optimization design of the coin chute flection curve

Qinghua LIANG, Jinqiu MO, Weizhong GUO

期刊论文

Deflection behavior of a prestressed concrete beam reinforced with carbon fibers at elevated temperatures

Mohammed FARUQI, Mohammed Sheroz KHAN

期刊论文