317 publications from this institution
As composite materials have advantages of high strength-to-weight ratio and superior corrosion resistance properties, it is used in emergencies in the construction of mobile bridges as the preferred material. However, In contrast to traditional steel or aluminum to the movement of the bridge as the main material, the original bridge forms need to be improved in order to reach the full of FRP material properties. In this paper, to study the domestic light-weight mobile FRP Bridge, the finite element method is used to analysis the mechanical properties of bridge.
No abstract is provided for this article.
Wet-bonding is a technique of connecting fiber reinforced polymer (FRP) profile and cast-in-place concrete, which is characterized by the simultaneous hardening of concrete and adhesive. The mechanical properties of wet-bonding interface have been investigated by researchers, but none of them considers the influence of lateral confinement which is commonly present in structures. The insufficient knowledge on wet-bonding consequently hinders its application in FRP-concrete hybrid structures. To this end, this paper investigates the bond properties of wet-bonding interface in confined concrete through pullout and pushout tests. Test results indicate that the interfacial behavior of wet-bonding interface can be divided into three stages. In the first stage, the interfacial resistance comes from the chemical bond of adhesive, and the lateral confinement is hardly activated. This stage comes to an end when the interface between adhesive and concrete fails. In the second and third stage, the interfacial resistance is mainly contributed by the friction between fractured surfaces of adhesive and concrete. The relative movement of fractured surfaces which are microscopically rough induces vertical movement and then activates the lateral confinement, resulting in lateral pressure and tangential friction. The significant friction behavior further damages the FRP-adhesive interface, leading to the final delamination of adhesive from the FRP plate. Based on the above force-transfer mechanism, a bond stress-slip model depending on the lateral pressure is developed. This interfacial model is implemented into Abaqus and its effectiveness is verified by comparing with test results.
In RC buildings, the unexpected sudden failure of a corner column is more likely to cause severe progressive collapse than the failure of an interior column or a side column due to the relatively weak tie force from the surrounding elements. Effective strengthening methods can improve the progressive collapse resistance of these structures. Fiber-reinforced polymer (FRP) has been widely used to retrofit RC structures due to its high strength, light weight, and corrosion resistance. In this study, the progressive collapse behaviors of glass FRP (GFRP)–strengthened RC beam–slab subassemblages under corner column removal were investigated. First, a quasi-static experimental test was adopted to study the progressive collapse resistance of the beam–slab subassemblages, including a control specimen and strengthened specimens. Two techniques applying externally bonded GFRP laminates and near-surface-mounted (NSM) GFRP bars were adopted to strengthen the subassemblages. The influences of the strengthening schemes on the behavior of the tested specimens were studied by comparing all the test results. The experimental results demonstrate that this strengthening technology can enhance the progressive collapse resistance of RC beam–slab structures. Finite-element (FE) analysis of the progressive collapse resistance of the beam–slab subassemblages was also conducted using the software package MSC Marc. The numerical model can predict the progressive collapse resistance of the subassemblages. In addition, the calculated results were used to better understand the stress distribution of the GFRP in a corner column–removal scenario.
With the increasing number of earth observing satellites and the growing demand for remote sensing data, satellite mission scheduling is undergoing a change from the traditional off-line mode to on-line mode. To overcome difficulties in handling large quantities of satellites and large-scale scenes by the current on-line multi-satellite mission scheduling method, we establish the mathematical model, design the computation framework based on multi-agent system contract net protocol. Then we put forward a load reduction method based on mean shift clustering for satellite scheduling agent and a bid evaluation method based on genetic algorithm for central cooperating agent. Finally, Experimental results are used to demonstrate the feasibility and effectiveness of the algorithms.
<title>Abstract</title> <bold>Ethnopharmacological Relevance:</bold> Zuo Gui Wan (ZGW), a traditional Chinese medicine (TCM) formula, shows potential for treating postmenopausal osteoporosis (PMOP), combining traditional herbal knowledge with modern scientific validation. <bold>Background:</bold> Postmenopausal osteoporosis (PMOP) is a metabolic bone disorder caused by estrogen deficiency, leading to decreased bone mass and increased fracture risk. ZGW has shown promise in managing PMOP, but its active metabolites and mechanisms remain unclear. <bold>Methods:</bold> Ovariectomized (OVX) rats were used to model osteoporosis. ZGW's efficacy was evaluated through micro-CT, HE staining, and serum ELISA. Active metabolites in serum were identified by UPLC-MS/MS. A "botanical drug-metabolite-target-disease" network was built using network analysis. Pathway enrichment was performed using GO and KEGG in R. Molecular docking of key metabolites and targets was conducted using AutoDock Vina and PyMOL. In vitro assays, including MTT, ALP, Alizarin Red S staining, PCR, and Western blotting, validated osteogenic effects. <bold>Results:</bold> ZGW improved bone microstructure and serum bone metabolism in OVX rats. UPLC-MS/MS identified 209 metabolites, with 20 transferring into the serum. PPI analysis revealed 144 key targets, and molecular docking showed strong binding between active metabolites (e.g., Remycin A, Farnesecin) and their targets, such as ALB and EGFR. GO and KEGG analyses identified pathways like HIF-1, estrogen signaling, and PI3K-Akt. In vitro, ZGW activated these pathways, enhancing osteogenic marker expression and promoting osteoblast proliferation and differentiation. <bold>Conclusion:</bold> ZGW treats PMOP through multiple mechanisms involving active metabolites, targets, and pathways. It restores normal gene expression and modulates pathways such as HIF-1 and PI3K-Akt, while also inhibiting inflammation. This study highlights the power of combining UPLC-MS/MS with network analysis for exploring TCM formulations in PMOP treatment.
No abstract is provided for this article.
Understanding how functional reasoning proceeds is crucial to further establish computer-aided tools for conceptual design. Enlightened by the symbiosis-based evolution theory of organism, this paper proposes a symbiosis-based functional reasoning model for original design, which is based on three kinds of symbiotic relations between product functions. The functional reasoning process of a wood stick-separated device then demonstrates that the model is valid.
No abstract is provided for this article.
Cables of suspended structures are suffering due to increased corrosion and fatigue loading.Since 1980 EMPA and BBR Ltd.in Switzerland have been developing Carbon Fiber Reinforced Polymer(CFRP) parallel wire bundles as cables for suspended structures.The excellent properties of those bundles include corrosion resistance,very high specific strength and stiffness,superior equivalent moduli and outstanding fatigue behavior.An anchoring scheme produced with gradient materials based upon ceramics and epoxy is described.For the first time large CFPR cables were applied in 1996 on the vehicular cable-stayed Stork Bridge with 124 m span in Winterthur, Switzerland.The performance of these cables and later applications was and still is monitored with sophisticated fiber optical monitoring systems.Up to date these results are fully matching the high expectations.Under the assumptions that(i) the behavior of the pilot applications of CFRP cables described in this paper is further on fully satisfactory,(ii) active systems for distributed mitigation of wind-induced vibrations are going to be successful and(iii) there is a need for very extremely long span bridges to cross straits like that of Bab el Mandeb,Messina or Gibraltar: why should the next generation of structural engineers not use CFRP cables for extremely long span bridges? This would open spectacular new opportunities.
Glass fiber-reinforced polymer (GFRP) composites have been increasingly used in the construction of civil structures because of their light weight and high strength, tailored flexibility, and corrosion resistance. Such structural materials also present potential for a multifunctional design where functions other than load-carrying capacity, such as thermal insulation, energy supply, and intelligent inspection can be incorporated into one GFRP structural component. This paper further extends this concept by the development of the self-luminous function. In this application, a translucent resin modified with self-luminous powders, together with the nature of glass fibers, is able to illuminate the resulting GFRP composite in darkness and therefore provide the structural members with new architectural and aesthetic features or other service signatures. Mechanical experiments, luminance measurements, and scanning electron microscopy (SEM) imaging have been conducted to examine the self-luminous GFRP composites, and the results are reported in this paper.
腐蚀和疲劳一直是悬索结构中的拉索所面临的主要问题,早在1980年瑞士EMPA和瑞士BBR有限公司就开始研发碳纤维增强复合材料（CFRP）平行缆索以用于悬索结构。CFRP索的优势包括耐腐蚀、高强度和高模量、较大的等效模量以及出色的疲劳性能。同时,也开发出一种基于陶瓷和环氧树脂的梯度材料锚固技术。1996年,CFRP索首次被应用于瑞士温特图尔的124m跨度斜拉公路桥中。这些以及此后应用的CFRP索一直用光纤进行监测,到目前为止,监测结果完全符合预先的期望。假设：①本文所描述的CFRP索的使用性能完全令人满意;②风振主动控制系统能够很好地工作;③需要一个超大跨度的桥梁来横跨某个水域,例如曼德海峡、直布罗陀海峡,那么新一代的结构工程师为什么不在超大跨桥梁中使用CFRP索呢？一旦使用,将会带来令人瞩目的新机遇。
随着国家农机购置补贴政策的大力实施,广大农民朋友的购机热情高涨。但由于缺乏足够的专业知识,在选购农机具的过程中,往往变得犹豫不决。特别是大中型农机局的选购,需要花费很大的一笔资金,千万不可以掉以轻心。因此,以下五点可供参考。一、适应性
A low power fast settling multi-standard CMOS fractional-N frequency synthesizer is proposed.The current reusing and frequency presetting techniques are adopted to realize the low power fast settling multi-standard fractional-N frequency synthesizer.An auxiliary non-volatile memory(NVM) is embedded to avoid the repetitive calibration process and to save power in practical application.This PLL is implemented in a 0.18μm technology. The frequency range is 0.3 to 2.54 GHz and the settling time is less than 5μs over the entire frequency range.The LC-VCO with the stacked divide-by-2 has a good figure of merit of-193.5 dBc/Hz.The measured phase noise of frequency synthesizer is about-115 dBc/Hz at 1 MHz offset when the carrier frequency is 2.4 GHz and the reference spurs are less than -52 dBc.The whole frequency synthesizer consumes only 4.35 mA @ 1.8 V.
Fiber reinforced polymer( FRP) materials are a relatively new material in civil and structural engineering,but due to their unique physical,chemical,and mechanical characteristics,they have gradually become an important part of the civil engineering materials toolkit. This paper surveys the use of FRP in structural reinforcement,cable elements,and prestressed concrete reinforcement,and discusses the development of FRP both in composite and pure-FRP structural applications. Furthermore,it highlights the development and present state of the various codes pertaining to the use of FRP in structural engineering in China with an eye towards encouraging better understanding and increased use of the material.
