Self-Contained Modal Testing Trailer for Bridge Health Assessment

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Solution Overview

Problem

Current methods for assessing bridge load capacity are either costly and time-consuming or require excessive expertise, limiting the ability to quantitatively determine the health of bridge populations, particularly for common highway bridges.

Innovation Solution

The Targeted Hits to Measure Performance Responses (THMPR) system combines a modal testing device with semi-automated modal analysis software and Rapid Automated Modeling for Performance of Structures (RAMPS) software for cost-effective bridge evaluation, using a self-contained rapid modal testing trailer and wireless data processing to extract modal parameters and develop refined load ratings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If static load testing is used to directly measure in-situ bridge characteristics, then measurement precision is improved, but device complexity and loss of time increase due to full bridge closure, loaded trucks, and numerous sensors required

Engineering Contradiction:
Improvedirect measurement of in-situ bridge characteristicsVSAvoidcomplexity of sensors and data acquisition equipment
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential measurement function from complex static load testing by using mobile impact devices that deliver controlled impulses directly to the bridge, eliminating the need for full bridge closure, multiple trucks, and extensive sensor arrays while capturing the necessary dynamic response characteristics

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical truck-loading system with a controlled impact device that delivers precise impulse forces, substituting complex mechanical load application with a simplified impact mechanism that achieves the same measurement objective through dynamic excitation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of time

If dynamic testing is used to capture global performance with lower time requirements, then loss of time is reduced, but difficulty of detecting and measuring increases due to significant user-expertise requirements

Engineering Contradiction:
Improvetime requirement for testingVSAvoiduser-expertise requirements
Core Design Contradiction:
Loss of timeVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements self-service through automated data processing and analysis algorithms that automatically interpret the dynamic response data, eliminating the need for expert operators to manually analyze complex vibration signals and enabling non-experts to perform reliable dynamic testing

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent incorporates real-time feedback through automated processing of dynamic response data, where the system automatically adjusts and interprets measurements during testing, providing immediate results without requiring expert intervention for data analysis

Inventive Principle:
Principle #23Feedback

3Measurement precision

If refined modeling and load testing procedures are used to assess critical structures, then measurement precision is improved, but loss of time and device complexity increase making them excessive for common bridges

Engineering Contradiction:
Improveassessment accuracy of bridge healthVSAvoidtime required for testing and analysis
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the bridge assessment into targeted impact tests at specific locations rather than requiring comprehensive full-bridge testing, allowing rapid extraction of critical modal parameters through localized excitation and measurement points

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using a limited number of strategically placed impact devices and sensors to capture the essential dynamic characteristics needed for accurate bridge assessment, rather than implementing exhaustive testing procedures

Inventive Principle:
Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The THMPR system provides a cost-competitive and efficient means to determine bridge health by extracting modal parameters and calibrating finite element models, enabling accurate load ratings and reducing the need for extensive testing and expertise, thus overcoming the limitations of existing methods.

Implementation Method 1

The apparatus uses a single, large (∼30 kip) broadband impact source

Methodology Applied
Scientific EffectImpact Force: Impact Force

Implementation Method 2

collect the resulting free-decay response of the bridge

Methodology Applied
Scientific EffectMechanical Vibration: Vibration

Data Source

PatentEP3158307B1Self-contained rapid modal testing system for highway bridges
Publication Date: 2021.08.04 DREXEL UNIV
  • EP3158307B1 patent drawingFigure 1
  • EP3158307B1 patent drawingFigure 2
  • EP3158307B1 patent drawingFigure 3

AI summary

A system for measuring structural integrity includes a self-contained rapid modal testing trailer that delivers an impact load to a structure being tested and records data resulting from the impact load, and a data processing software that extracts modal parameters of the structure, such as frequencies and mode shapes. The parameters are used to determine anomalous behavior as well as provide experimental data for finite element model calibration.