All-GFRP footbridge under human-induced excitation

The dynamic behavior of lively footbridge is a complex problem. Recently there were numerous publications and recommendations related to the dynamic nature of footbridge. The complicated procedure which was set in a number of instructions and standards says nothing about actions aimed at avoiding critical frequency range in structure. In the paper, results of dynamic in-situ tests of cable-stayed all-GFRP (Glass Fiber Reinforced Polymer) footbridge are presented. Fiberline Footbridge, located in Kolding city in Denmark, was constructed in 1997 using 12 different pultruded profiles all made of GFRP material. The dynamic characteristics as well as vertical response of the tested footbridge under human excitation are given and discussed. Firstly, in order to estimate the dynamic properties of the footbridge, a series of free-decay responses under human jumping were conducted. The fundamental frequency of the analyzed structure was within a critical range. A methodology for footbridge classification with regard to their dynamic sensitivity was worked out and the correlation between the structure's properties and its dynamic response under pedestrian excitation was formulated. It was found that the analyzed footbridge fulfilled vibration comfort criteria elaborated by technical guide Sétra, however, more restricted acceleration limits suggested by Eurocode were not met.

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Evaluation of Stiffness and Dynamic Properties of a Mine Shaft Steelwork Structure through In Situ Tests and Numerical Simulations

Energies ◽

10.3390/en14030664 ◽

2021 ◽

Vol 14 (3) ◽

pp. 664

Author(s):

Jacek Jakubowski ◽

Przemysław Fiołek

Keyword(s):

Numerical Simulations ◽

Dynamic Properties ◽

Vertical Motion ◽

Load Test ◽

Mode Shapes ◽

Dynamic Amplification Factor ◽

In Situ Tests ◽

Mine Shaft ◽

Numerical Investigations

A mine shaft steelwork is a three-dimensional frame that directs the vertical motion of conveyances in mine shafts. Here, we conduct field and numerical investigations on the stiffness and dynamic properties of these structures. Based on the design documentation of the shaft, materials data, and site inspection, the steelwork’s finite element model, featuring material and geometric non-linearities, was developed in Abaqus. Static load tests of steelwork were carried out in an underground mine shaft. Numerical simulations reflecting the load test conditions showed strong agreement with the in situ measurements. The validated numerical model was used to assess the dynamic characteristics of the structure. Dynamic linear and non-linear analyses delivered the natural frequencies, mode shapes, and structural response to dynamic loads. The current practices and regulations regarding shaft steelwork design and maintenance do not account for the stiffness of guide-to-bunton connections and disregard dynamic factors. Our experimental and numerical investigations show that these connections provide considerable stiffness, which leads to the redistribution and reduction in bending moments and increased stiffness of the construction. The results also show a high dynamic amplification factor. The omission of these features implicates an incorrect assessment of the design loads and can lead to over- or under-sized structures and ultimately to shortened design working life or failure.

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In situ sensing in glass fiber-reinforced polymer composites via embedded carbon nanotube thin films

Innovative Developments of Advanced Multifunctional Nanocomposites in Civil and Structural Engineering ◽

10.1016/b978-1-78242-326-3.00014-2 ◽

2016 ◽

pp. 327-352

Author(s):

Bryan R. Loyola

Keyword(s):

Thin Films ◽

Carbon Nanotube ◽

Polymer Composites ◽

Fiber Reinforced Polymer ◽

Glass Fiber Reinforced Polymer ◽

Reinforced Polymer ◽

Glass Fiber Reinforced ◽

Fiber Reinforced Polymer Composites ◽

In Situ Sensing

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Dynamic Identification of an Early 20th Century Civil Architectural Building

Civil Engineering Journal ◽

10.28991/cej-2020-03091499 ◽

2020 ◽

Vol 6 (4) ◽

pp. 670-678 ◽

Cited By ~ 1

Author(s):

Bilal Muhammed Bağbancı

Keyword(s):

Finite Element ◽

Mechanical Test ◽

Dynamic Properties ◽

Mode Shapes ◽

Finite Element Models ◽

In Situ Tests ◽

Historical Structures ◽

Reinforced Concrete Slabs ◽

Construction Techniques

Historical structures are important in terms of both original construction techniques and cultural heritage. Therefore, material properties, construction techniques and dynamic behaviors of these structures must be identified in order to preserve them in the future by restoration studies. This study is aimed to serve as an example for similar buildings in the region whose walls were constructed using filled brick with lime mortar and constructed using both timber and reinforced concrete slabs. In this study, the plan layout, construction techniques and the material usage of the building were investigated in detail. The mechanical and dynamic properties such as compressive stress, elastic moduli, shear stress, natural frequencies and mode shapes of the building were determined in-situ by flat-jack, shear and vibration tests. The finite element model of the structure was prepared, and the modal analysis of the structure was performed. The calibration of the model was ensured according to the vibration test results. The results obtained from this study show us that in-situ tests are extremely important for the accuracy of finite element models. It has been determined that the mechanical test data can be used with over 80% success in finite element models.

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Interpretation of sensor data from in situ tests on a transversely bonded fibre-reinforced polymer road bridge

Structural Health Monitoring ◽

10.1177/1475921718779403 ◽

2018 ◽

Vol 18 (4) ◽

pp. 1074-1091

Author(s):

Wendel Michael Sebastian ◽

Mike Johnson

Keyword(s):

Sensor Data ◽

In Situ Tests ◽

Reinforced Polymer ◽

Fibre Reinforced Polymer

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DESIGN AND EXAMINATION OF STRUCTURAL AND DYNAMIC PROPERTIES OF SAVONIUS VERTICAL AXIS WIND TURBINE BLADE MADE OF ALUMINUM AND GLASS FIBER REINFORCED POLYMER

Strad Research ◽

10.37896/sr7.7/062 ◽

2020 ◽

Vol 7 (7) ◽

Keyword(s):

Wind Turbine ◽

Glass Fiber ◽

Turbine Blade ◽

Dynamic Properties ◽

Vertical Axis ◽

Fiber Reinforced Polymer ◽

Vertical Axis Wind Turbine ◽

Glass Fiber Reinforced Polymer ◽

Reinforced Polymer ◽

Glass Fiber Reinforced

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Assessment of human-induced vibrations of a cable-stayed footbridge

MATEC Web of Conferences ◽

10.1051/matecconf/201821109001 ◽

2018 ◽

Vol 211 ◽

pp. 09001 ◽

Cited By ~ 1

Author(s):

Izabela Drygała ◽

Joanna M. Dulinska ◽

Marek Wazowski

Keyword(s):

Natural Frequencies ◽

Dynamic Properties ◽

Three Dimensional ◽

Fe Model ◽

In Situ Tests ◽

Modal Assurance Criterion ◽

Comfort Criteria ◽

Abaqus Software

The primary purpose of this research is the evaluation of human-induced vibrations of a cable-stayed footbridge. The cable-stayed pedestrian bridge with total length of the span equal to 46.90 m located in Czestochowa (Southern Poland) was chosen as a case study. The footbridge consists of two spans (21.10 m and 25.80 m). A three-dimensional (3D) finite element (FE) model of the footbridge was prepared with the ABAQUS software program. The dynamic properties of the structure, i.e. its natural frequencies, modes shapes and damping ratios, were estimated on the basis of the in situ tests results as well as numerical analysis. For the validation of the modal models the modal assurance criterion (MAC) theory was applied. In the next stage of the investigation the dynamic response of the structure to human-induced loading was evaluated. Finally, the vibration comfort criteria for the footbridge were checked.

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