Monitoring and Defect Detection of an All-Composite Road Bridge

2000 ◽  
Author(s):  
Roger M. Crane ◽  
John W. Gillespie ◽  
Dirk Heider ◽  
Douglas A. Eckel ◽  
Colin P. Ratcliffe
Keyword(s):  
Structural Integrity ◽  
Theoretical Calculations ◽  
Detection Algorithm ◽  
Mode Shapes ◽  
Manufacturing Defects ◽  
Vibration Data ◽  
Composite Bridges ◽  
Longitudinal Joint ◽  
Composite Bridge ◽  
Sandwich Core

Abstract This paper presents the results of an ongoing investigation into the use of broadband vibration data to monitor the structural integrity and health of an all-composite road bridge. Bridge 1-351 on Business Route 896 in Glasgow, Delaware, was replaced with one of the first state-owned all-composite bridges in the nation in the fall of 1998. The bridge consists of two E-Glass/vinyl ester sandwich core sections (13-ft × 32 ft) joined by a longitudinal joint in the traffic direction. Each sandwich core section consists of a 28-inch deep core and 0.4-0.7-inch thick facesheets. Vibration data were obtained from the upper and lower surfaces of the bridge using a mesh of 1050 test points. From the modal information and the visualization of the data, several aspects of the structural behavior of the bridge were obtained. These characteristics include the interactions between the bridge and abutments; the effectiveness of the longitudinal joint to couple the deck sections; the effectiveness of the core to couple the face sheets; and the structural integrity and dynamic consistency of the entire structure. Mode shapes and natural frequencies were determined and are correlated with theoretical calculations and vibration analyses conducted for this bridge. A novel algorithm using the vibration data is being developed that enables local perturbations sensitive to the state of the material (e.g. manufacturing defects, material degradation or service damage) to be detected and spatially located in the bridge. This technique has been successfully validated for locating damage in 1-D beam structures and is being extended to the 3-D sandwich configuration of the bridge. By coupling this damage detection algorithm with the more conventional modal technique, the quality assurance/quality control and health monitoring of large composite bridge can be obtained.

Fractal Characteristics of Sandstone Cutting Fracture under Mechanical Shock Loading Conditions

2012 ◽  
Vol 226-228 ◽  
pp. 1789-1794 ◽  
Author(s):  
Shu Ren Wang ◽  
Paul Hagan ◽  
Yan Cheng
Keyword(s):  
Fractal Dimension ◽  
Size Distribution ◽  
Structural Integrity ◽  
Theoretical Calculations ◽  
Mesh Size ◽  
Rock Cutting ◽  
Weight Percent ◽  
Rock Breaking ◽  
Engineering Practice ◽  
Mechanical Shock

It is the key to guide rock-breaking design and engineering practice for how to obtain a reasonable test indicator to assess the cuttability of the rock. Some sandstone samples were tested by using the linear rock cutting machine in the school of mining engineering, University of New South Wales (UNSW), Australia. The curves characteristics for the weight percent of the broken debris with the mesh size distribution were obtained through the screening statistics. Furthermore, the fractal dimension of the specimen broken debris was derived through theoretical calculations and statistical analysis. The results showed that the rock cutting fragmentation is of significant fractal features under the mechanical shock loads. The broken debris fractal dimension of the structural integrity specimens is bigger, the range of the fractal dimension is smaller and the broken debris size distribution is more even than that of the poor structural integrity specimens. The fractal dimension is the ideal test indicator to assess and analysis the rock-breaking degree.

scholarly journals Automated band selection for Bayesian FFT modal identification Based on RetinaNet

2021 ◽  
Vol 2078 (1) ◽  
pp. 012058
Author(s):  
Chen Wang ◽  
Zhilin Xue ◽  
Yipeng Su ◽  
Binbin Li
Keyword(s):  
Operation Time ◽  
Modal Identification ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Band Selection ◽  
Data Sets ◽  
Civil Structures ◽  
Frequency Bands ◽  
Operational Conditions ◽  
Vibration Data

Abstract Bayesian FFT algorithm is a popular method to identify modal parameters, e.g., modal frequencies, damping ratios, and mode shapes, of civil structures under operational conditions. It is efficient and provides the identification uncertainty in terms of posterior distribution. However, in utilizing the Bayesian FFT algorithm, it is tedious to manually select frequency bands and initial frequencies. This step requires professional knowledge and costs most of time, which prevents the automation of Bayesian FFT algorithm. Regarding the band selection as an object detection problem, we design a band selection network based on the RetinaNet to automatically select frequency bands and a peak prediction network to predict the initial frequencies. The designed networks are trained using the singular value spectrum of measured ambient vibration data and verified by various data sets. It can achieve the human accuracy with much less operation time, and thus provides a corner stone for the automation of Bayesian FFT algorithm.

scholarly journals DESIGN OF PERKUWEN BRIDGE PART WAY LONG IKIS-LAMBAKAN PASER TANA PASER REGENCY PROVINCE EAST KALIMANTAN

CERUCUK ◽  
2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Humaira Afrila ◽  
Markawie Markawie
Keyword(s):  
Design Method ◽  
Plate Thickness ◽  
Steel Structures ◽  
Structure Design ◽  
Steel Pipe ◽  
Pipe Pile ◽  
East Kalimantan ◽  
Composite Bridges ◽  
Composite Bridge ◽  
Steel Pipe Pile

Long Kali is a sub-district of Paser Tana Paser Regency Prov. East Kalimantan. In this sub-district have two village separate by a river, that is Perkuwen river, there is bridge has a broke. Whereas the village very needed a bridge because it is used as a transportation infrastructure for peoples and also passed by vehicles transporting oil palm yields . Therefore, the design of composite bridges made with spans 25 m and 7 m wide bridge.In this plan the analysis of Standard methods of loading refers to the bridge imposition For RSNI T-02-2005 about composite bridge structure design method, refers to RSNI T-03-2005 about Steel Structural Design For Bridge, SNI 03-1729-2002 about Steel Structures Planning Procedures and SNI 03-2847-2002 about Concrete Structures Calculation for Building.The result is used the main girder profile SH 950 x 400 x 16 x 32 and diaphragm WF 400 x 200 x 8 x 13. Vehicle floor plate thickness 20 cm using quality concrete  30 MPa and quality reinforcing steel reinforcement  360 MPa with subject dividers reinforcement D22- 100 and D12-100 mm. In using concrete pavement  30 MPa D22-100 mm staple reinforcement and shear reinforcement rebars quality D12-100 mm  360 MPa. Concrete abutment in the form  25 MPa at 2 m height and length of 8,5 m. Steel pipe pile foundations quality  25 MPa are 16 pieces with a length of 10 meters and a diameter of 0.4 m.Keyword: Bridge, composite, steel pipe pile.

L1 Regularized Model Updating for Structural Damage Detection

2018 ◽  
Vol 18 (12) ◽  
pp. 1850157 ◽  
Author(s):  
Yu-Han Wu ◽  
Xiao-Qing Zhou
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Model Updating ◽  
Regularization Parameter ◽  
Structural Vibration ◽  
Mode Shapes ◽  
Modal Data ◽  
Vibration Data ◽  
Stiffness Reduction ◽  
Regularized Model

Model updating methods based on structural vibration data have been developed and applied to detecting structural damages in civil engineering. Compared with the large number of elements in the entire structure of interest, the number of damaged elements which are represented by the stiffness reduction is usually small. However, the widely used [Formula: see text] regularized model updating is unable to detect the sparse feature of the damage in a structure. In this paper, the [Formula: see text] regularized model updating based on the sparse recovery theory is developed to detect structural damage. Two different criteria are considered, namely, the frequencies and the combination of frequencies and mode shapes. In addition, a one-step model updating approach is used in which the measured modal data before and after the occurrence of damage will be compared directly and an accurate analytical model is not needed. A selection method for the [Formula: see text] regularization parameter is also developed. An experimental cantilever beam is used to demonstrate the effectiveness of the proposed method. The results show that the [Formula: see text] regularization approach can be successfully used to detect the sparse damaged elements using the first six modal data, whereas the [Formula: see text] counterpart cannot. The influence of the measurement quantity on the damage detection results is also studied.

scholarly journals Modal and Vibration Analysis of Filter System in Petrochemical Plant

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Zhongchi Liu ◽  
Ji Wang ◽  
Wie Min Gho ◽  
Xiao Liu ◽  
Xuebing Yu
Keyword(s):  
Structural Integrity ◽  
Natural Frequencies ◽  
Resonance Effect ◽  
Petrochemical Plant ◽  
Structural Fatigue ◽  
Filter System ◽  
Vibration Data ◽  
Finite Element Software ◽  
Vibration Problem ◽  
System A

Filter systems are widely used in petrochemical plants for removing solid impurities from hydrocarbon oils. The backwash is the cleaning process used to remove the impurities on the sieves of the filters without a need to interrupt the operation of the entire system. This paper presents a case study based on the actual project of a filter system in a petrochemical plant, to demonstrate the significant effect of vibration on the structural integrity of piping. The induced vibration had led to the structural fatigue failure of the pipes connecting the filter system. A preliminary assessment suggested that the vibrations are caused by the operation of backwashing of the filter system. A process for solving the vibration problem based on the modal analysis of the filter system using the commercial finite element software for simulation is therefore proposed. The computed natural frequencies of the system and the vibration data measured on site are assessed based on the resonance effect of the complete system including the piping connected to the filters. Several approaches are proposed to adjust the natural frequencies of the system in such a way that an optimal and a reasonable solution for solving the vibration problem is obtained.

Bridge 1-351 over Muddy Run: Design, Testing, and Erection of an All-Composite Bridge

2000 ◽  
Vol 1696 (1) ◽  
pp. 118-123 ◽  
Author(s):  
J. W. Gillespie ◽  
D. A. Eckel ◽  
W. M. Edberg ◽  
S. A. Sabol ◽  
D. R. Mertz ◽  
...  
Keyword(s):  
Large Scale ◽  
Flexural Rigidity ◽  
Limit State ◽  
Engineering Properties ◽  
Molding Process ◽  
Strength Limit ◽  
Large Scale Testing ◽  
Longitudinal Joint ◽  
Composite Bridge

Bridge 1.351 on Business Route 896 in Glasgow, Delaware, was replaced with one of the first state-owned all-composite bridges in the nation. Composites are lightweight construction materials that do not corrode, which results in benefits such as ease of construction and reduced maintenance costs. A summary of the design, large-scale testing, fabrication, erection, and monitoring of this bridge is presented. The bridge was designed to AASHTO load and resistance factor design specifications. A methodology was developed to incorporate the engineering properties of these unique composite materials into the design. The bridge consists of two 13 × 32 ft (3.96 × 9.75 m) sections joined by a unique longitudinal joint. The sections have sandwich construction consisting of a core [28 in. (71.12 cm) deep] and facesheets [0.4 to 0.6 in. (10.16 to 15.24 mm) thick] that provide shear and flexural rigidity, respectively. The composite bridge was fabricated with E-glass preforms and vinyl-ester resin, which offers excellent structural performance and long-term durability. Each of the sections was fabricated to near-net shape in a single step by a vacuum-assisted resin transfer molding process. The overall structural behavior has been accurately predicted with simple design equations based on sandwich theory for anisotropic materials. Large-scale testing of full-sized subcomponents was conducted to prove that the design satisfied deflection, fatigue, and strength limit states. A redundant longitudinal joint was designed that consisted of both an adhesively bonded vertical joint between sections and splice plates. Assembly procedures were developed, and transverse testing of the full-sized joint was conducted. Final bridge sections were proof-tested to the strength limit state. The construction phase included section positioning, joint assembly, and application of a latex-modified concrete wear surface. The bridge was reopened to traffic on November 20, 1998. Results from the long-term monitoring effort will be documented.

Influence of People Walking on Floor Performance due to Low Level Vibration

2015 ◽  
Vol 802 ◽  
pp. 208-213
Author(s):  
Tuan Norhayati Tuan Chik ◽  
Shurl Yabi ◽  
Mohd Haziman Wan Ibrahim ◽  
Nor Azizi Yusoff ◽  
Taksiah A. Majid ◽  
...  
Keyword(s):  
Software Package ◽  
Laser Doppler Vibrometer ◽  
Vibration Response ◽  
Dynamic Loads ◽  
Mode Shapes ◽  
Low Level ◽  
Vibration Data ◽  
Finite Element Software ◽  
Floor Structure ◽  
Floor Vibrations

Abstract. Vibration in building is one of the important problems which need to consider, especially in designing the floor. Floor vibrations are generally caused by dynamic loads applied particularly by human activity especially walking. Although it is specified as low level amplitude, walking induced vibrations can cause discomfort to human occupants and alarming for a certain items of precision sensitive equipment. This paper investigates the vibration response on floor performance due to one, three and five of people walking. Laser Doppler Vibrometer was used to obtain vibration data when people are walking. Further analysis was carried out by using finite element software package ANSYS to simulate the floor under vibration inputs to obtain natural frequency and mode shapes of the floor structure. The vibration data was then analysed in ModalV analysis to generate the vibration response. Then, the results were checked against the vibration criteria level guideline as a crude tool comparison. As a result, the numbers of people walking were influenced the floor performance, which indicated five peoples walking show the highest response up to ISO level due to vibration compared with one people walking.

Experimental investigation into the use of vibration data for long-term monitoring of an all-composite bridge

2000 ◽  
Author(s):  
Colin P. Ratcliffe ◽  
John W. Gillespie, Jr. ◽  
Dirk Heider ◽  
Douglas A. Eckel II ◽  
Roger M. Crane
Keyword(s):  
Experimental Investigation ◽  
Vibration Data ◽  
Composite Bridge ◽  
Long Term Monitoring ◽  
Term Monitoring

Updating the Mathematical Model of a Structure Using Vibration Data

2005 ◽  
Vol 11 (12) ◽  
pp. 1469-1486 ◽  
Author(s):  
Ashutosh Bagchi
Keyword(s):  
Mathematical Model ◽  
Model Updating ◽  
Three Dimensional ◽  
Field Tests ◽  
Mode Shapes ◽  
Actual Structure ◽  
Shell Elements ◽  
Vibration Data ◽  
The Difference ◽  
The Mathematical Model

Model updating is an important step for correlating the mathematical model of a structure to the real one. There are a variety of techniques available for model updating using dynamic and static measurements of the structure’s behavior. This paper concentrates on the model updating techniques using the natural frequencies or frequencies and mode shapes of a structure. An iterative technique is developed based on the matrix update method. The method hasbeenappliedtothefiniteelement models of a three span continuous steel free deck bridge located in western Canada. The finite element models of the bridge have been constructed using three-dimensional beam and facet shell elements and the models have been updated using the measured frequencies. From the study it is clear that the initial model needs to be built such that it represents the actual structure as closely as possible. The results demonstrate that the difference between the modal parameters from the model and field tests affect the quality of the model updating process.

Extending Blind Modal Identification to the Underdetermined Case for Ambient Vibration

2012 ◽  
Author(s):  
Scot McNeill
Keyword(s):  
Natural Frequencies ◽  
Second Order ◽  
Modal Identification ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Frequency Domain Method ◽  
Blind Identification ◽  
Vibration Data ◽  
Modal Damping ◽  
Six Dof

The modal identification framework known as Blind Modal Identification (BMID) has recently been developed, drawing on techniques from Blind Source Separation (BSS). Therein, a BSS algorithm known as Second Order Blind Identification (SOBI) was adapted to solve the Modal IDentification (MID) problem. One of the drawbacks of the technique is that the number of modes identified must be less than the number of sensors used to measure the vibration of the equipment or structure. In this paper, an extension of the BMID method is presented for the underdetermined case, where the number of sensors is less than the number of modes to be identified. The analytic signal formed from measured vibration data is formed and the Second Order Blind Identification of Underdetermined Mixtures (SOBIUM) algorithm is applied to estimate the complex-valued modes and modal response autocorrelation functions. The natural frequencies and modal damping ratios are then estimated from the corresponding modal auto spectral density functions using a simple Single Degree Of Freedom (SDOF), frequency-domain method. Theoretical limitations on the number of modes identified given the number of sensors are provided. The method is demonstrated using a simulated six DOF mass-spring-dashpot system excited by white noise, where displacement at four of the six DOF is measured. All six modes are successfully identified using data from only four sensors. The method is also applied to a more realistic simulation of ambient building vibration. Seven modes in the bandwidth of interest are successfully identified using acceleration data from only five DOF. In both examples, the identified modal parameters (natural frequencies, mode shapes, modal damping ratios) are compared to the analytical parameters and are demonstrated to be of good quality.

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