Accelerated Pavement Testing Device Using Segmented Actuators
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Solution Overview
Problem
Current accelerated pavement testing devices are limited by low testing speed, inadequate simulation of dynamic loading, continuous stress without rest periods, and inability to accurately simulate real traffic patterns, leading to inefficient evaluation of new materials and methods.
Innovation Solution
A method and device that simulate wheel loading by applying a series of discreet forces with a downwards component, using actuators and force transfer elements to mimic the effect of traveling wheels, allowing for adjustable force magnitude, frequency, and sequence to simulate various traffic conditions, including rest periods and dynamic loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional mobile APT devices (HVS, ALF, MLS) are used to simulate heavy traffic, then pavement testing can be conducted on real roads, but the testing speed is low (less than 25 km/h) due to the physical configuration and energy requirements
Solution Approach 1:
The testing device is divided into multiple independent actuators (at least 5, preferably at least 15) that can be controlled separately. Each actuator applies force to different portions of the pavement test strip, allowing parallel processing of loading conditions and enabling higher testing speeds by distributing the simulation workload across multiple independent units rather than relying on a single bogie system.
Solution Approach 2:
The traditional mechanical bogie-based loading system is replaced with an array of controlled actuators that can be actuated electrically, hydraulically, or pneumatically. This substitution eliminates the physical constraints of accelerating and decelerating heavy bogies, allowing for higher testing speeds while maintaining the ability to simulate various traffic loading conditions.
2Force
If dual tyre truck bogies are used to simulate heavy traffic, then real road conditions can be tested, but the loading produced is low due to the slowness of the moving wheel load
Solution Approach 1:
The system dynamically adjusts the magnitude, frequency, and sequence of forces applied by individual actuators to simulate various traffic conditions. The actuators can be controlled to apply higher forces at higher frequencies to represent heavy vehicle loading, while the ability to vary these parameters dynamically allows the system to produce adequate loading effects without being constrained by the slow movement of physical bogies.
Solution Approach 2:
The system changes the parameters of applied forces (magnitude, frequency, duration, sequence) to accurately represent different traffic loading conditions. By adjusting these parameters, the device can produce high loading effects equivalent to heavy vehicles while maintaining the ability to test at higher speeds, as the loading characteristics are controlled through parameter variation rather than physical mass acceleration.
3Reliability
If continuous stream of traffic is simulated by existing devices, then testing can be performed, but the pavement remains in a stressed state without rest periods that does not accurately reflect real conditions
Solution Approach 1:
The system implements periodic action by controlling the actuators to apply loading in discrete, sequential intervals rather than continuously. The actuators can be activated and deactivated in a pattern that simulates real traffic flow with rest periods between loading events. This periodic activation allows the pavement to experience stress and recovery cycles that accurately reflect real road conditions, improving the reliability of the testing results.
4Reliability
If existing devices simulate traffic loading, then testing can be conducted, but they cannot accurately simulate dynamic loading from vehicle body movement and tyre hop
Solution Approach 1:
The system segments the dynamic loading simulation into multiple independent actuator responses. Each actuator can be controlled to apply forces with varying frequencies and magnitudes that individually represent different aspects of vehicle dynamics such as suspension movement and tyre hop. This segmentation allows the system to combine multiple simplified dynamic effects to create an overall accurate simulation of complex vehicle-pavement interaction without requiring a single complex mechanical system.
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
This approach enables faster and more accurate simulation of pavement behavior, allowing for the evaluation of new materials and methods in a shorter timeframe, simulating real traffic conditions and dynamic loading effects, thereby improving design and predicting future pavement performance.
Implementation Method 1
repeatedly applying a plurality of discreet forces with a downwards component, in series and one after the other, to an upper surface of a test strip of the pavement thereby to simulate a load exerted by a travelling wheel
Data Source
AI summary
A method of testing pavement includes repeatedly simulating wheel loading on the pavement by repeatedly applying a plurality of discrete forces with a downwards component, in series and one after the other, to an upper surface of a test strip of the pavement thereby to simulate a load exerted by a travelling wheel and hence subjecting the pavement to accelerated testing. The discrete forces are provided by repeatedly actuating a series of actuators, one after the other, each to exert a force with a downwards component to the upper surface of the test strip of pavement, or to a portion thereof.