Rotor Blade Test Bench with Static Prestressing
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Solution Overview
Problem
Existing test stands for rotor blades, particularly those for wind turbines, inadequately simulate the operating loads that occur in real operation, including lift forces, which limits the accuracy of vibration testing.
Innovation Solution
A test stand with a support structure and an excitation unit that applies a static prestressing force with a component perpendicular to the rotor blade, using load means connected via a flexible or rigid traction device, and incorporating a spring element to enhance vibration behavior, allowing simulation of realistic operating loads and reducing test time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional test stand with hydraulic cylinder and lever arrangement is used, then the oscillating mass is reduced and deflection is limited, but the test stand cannot accurately simulate real operating loads including lift forces
Solution Approach 1:
The patent changes the fundamental loading parameters by introducing a load means that can apply static prestressing forces with components perpendicular to the rotor blade, simulating real operating conditions including lift forces. This transforms the test stand from a simple vibration exciter to a realistic operating condition simulator.
Solution Approach 2:
The invention makes the test stand dynamically adjustable by providing multiple load means that can be positioned at different locations along the rotor blade. The articulation point can be moved between test cycles, and the magnitude and direction of prestressing forces can be varied to simulate different operating scenarios.
2Productivity
If the rotor blade is tested with conventional vibration testing methods, then the test procedure is simple, but the test period is excessively long due to low natural vibration frequency
Solution Approach 1:
The patent employs spring elements connected to the rotor blade that can be adjusted to increase the natural vibration frequency. By optimizing the vibration characteristics through these spring elements, the test stand achieves faster oscillation cycles and reduces the overall test period while maintaining test validity.
3Reliability
If multiple load means are provided at different positions on the rotor blade, then realistic operating loads including lift forces can be simulated, but the device complexity increases
Solution Approach 1:
The load means are designed as multi-functional components that can serve multiple purposes: applying prestressing forces, positioning at different articulation points, and simulating various operating conditions. This universal design reduces the need for multiple specialized devices while maintaining test realism.
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
Enables more accurate and efficient vibration testing by simulating real operating loads, including lift forces, and shortening the test period by increasing natural vibration frequency.
Implementation Method 1
A spring element is connected to the load means and arranged between the load means and the rotor blade or the rotor blade segment, so that the rotor blade or the rotor blade segment can be acted upon by the spring element with a spring force in order to influence the vibration behavior
Data Source
Figure 1
Figure 2
AI summary
The test stand has a support structure (15) that is fastened at the axial end of a rotor blade (10) or the rotor blade segment. A stimulation unit is connected to the excitation of an oscillation of the rotor blade or the rotor blade segment. A load portion (31) is connected to a stationary articulation point for the test operation so that the static bias force is applied on the rotor blade or the rotor blade segment to run the component vertically. The load portion is formed by a motor such as an electrically driven motor. Independent claims are included for the following: (1) a test bench mounted in teat bench assembly; and (2) a method for operating a test bench.