Resonance Test Rig for Rotational Bending via Coupling Rods
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Solution Overview
Problem
Existing resonance test devices are inefficient in applying multidimensional loads, particularly for rotational bending in symmetrical components like wheel sets on rail vehicles, requiring high test forces and foundation loads, and are not suitable for lightweight construction.
Innovation Solution
A resonance test rig where the test specimen is supported on a machine table with actuators transmitting oscillating forces via coupling rods, allowing for minimal excitation forces and low drive energy, with the system operating at or near the resonance frequency to maximize vibration energy and avoid environmental energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the test specimen is firmly connected to additional masses and springs as in known resonance testing devices, then the test method can be implemented, but the requirements of operational test conditions are only satisfied to a limited extent and high test forces are required
Solution Approach 1:
The patent applies mechanical vibration by supporting the test specimen in a stationary manner on the machine table and using actuators to cause the test object to vibrate at or near its resonance frequency. This vibration approach enables operational testing while significantly reducing the test forces required compared to traditional firm connection methods with additional masses and springs.
Solution Approach 2:
The patent changes the fundamental parameter of how the test specimen is connected - from firm mechanical connection to stationary support with vibration excitation. This parameter change allows the system to operate at resonance frequency, achieving both operational test condition satisfaction and reduced force requirements.
2Reliability
If high test forces are used to achieve operational test conditions, then the testing can be performed, but the machine must be manufactured as a heavy construction and separate foundations are required
Solution Approach 1:
By using resonance vibration to perform the testing, the system achieves operational test conditions with minimal excitation forces. This eliminates the need for heavy machine construction and separate foundations, as the test specimen itself absorbs the main forces during resonant vibration.
Solution Approach 2:
The test specimen itself serves as the structure that absorbs the main forces during testing. By exciting the specimen at its resonance frequency, the specimen's own structural properties are utilized to handle the test forces, eliminating the need for the machine structure to be heavily constructed to bear these forces.
3Productivity
If the actuators are connected to the test specimen directly, then the testing can be performed, but vibration energy is lost to the environment and high drive energy is required
Solution Approach 1:
The patent uses resonance vibration where the actuators excite the test specimen at its natural resonant frequency. This creates a self-sustaining vibration system where energy is efficiently transferred and amplified, minimizing energy loss to the environment and reducing the drive energy required from the actuators.
Solution Approach 2:
By changing the operating parameter to resonance frequency, the system achieves maximum energy efficiency. The resonance increase of the transfer function amplifies the vibration energy, allowing minimal excitation forces to produce the required test conditions without significant energy loss.
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 solution enables high-frequency, accurate testing with reduced apparatus expenditure, allowing for a lightweight construction and eliminating the need for separate foundations, while minimizing disturbances from unbalance influences.
Implementation Method 1
The test object is excited by the actuator to oscillate at its resonant frequency, whereby the resonance increase of the transfer function of the oscillating system can be used
Implementation Method 2
coupling rods transmit the forces corresponding to the exciter vibration set to the test piece
Data Source
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AI summary
In a device for stress testing of rotating test specimens by mechanically applying periodically oscillating forces of at least one vibration system, which includes one or more actuators (12, 15) for generating an excitation vibration, a test specimen is fixedly supported on a machine table (1) and horizontally mounted at its opposite ends in the direction of the axis of rotation of the test specimen; at least one end of the test specimen is coupled to an actuator (12) in a substantially backlash-free manner via at least three coupling rods (10) arranged uniformly around a circumference around the axis of rotation of the test specimen, such that the coupling rods (10) transmit forces corresponding to the set excitation vibration to the test specimen for testing the rotational bending.