Quasi-Zero Stiffness Isolator Test Rig With Adjustable Stiffness
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Solution Overview
Problem
Current quasi zero stiffness isolator test platforms face challenges with inflexible stiffness adjustment, complex structures, inconvenient replacement of device elements, and complicated loading processes, which hinder effective vibration isolation and measurement accuracy.
Innovation Solution
A test device with a negative stiffness adjusting mechanism, a positive stiffness adjusting mechanism, and a beam-damping block mechanism allows for flexible adjustment of overall stiffness, stabilizes longitudinal vibration, and facilitates easy replacement of stiffness elements, utilizing a lead screw handwheel, hollow steel plate, and damping block mechanisms to achieve precise stiffness control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If several stiffness elements are combined to build a quasi zero stiffness isolator test platform, then the isolator can be constructed, but the adjustment of the range of device stiffness is not flexible and the structure becomes complicated
Solution Approach 1:
The patent employs a movable hollow steel plate that can be dynamically adjusted in position along the beam axis. This dynamic positioning capability allows continuous adjustment of the positive stiffness contribution, enabling flexible stiffness range adjustment without requiring multiple discrete stiffness elements or complex reconfiguration mechanisms.
Solution Approach 2:
The patent changes the geometric parameter (position) of the hollow steel plate to adjust the system stiffness. By varying the position parameter of a single component rather than changing the stiffness parameter of multiple components, the system achieves flexible stiffness adjustment with simplified structure.
2Adaptability or versatility
If multiple stiffness elements are used to achieve quasi zero stiffness, then the stiffness can be adjusted, but the device elements are inconvenient to replace and the loading of stiffness elements is more complicated
Solution Approach 1:
The patent extracts the negative stiffness function into a separate, self-contained module (the hollow steel plate assembly) that can be independently adjusted and replaced. This modular extraction allows the negative stiffness element to be moved, removed, or replaced without affecting the positive stiffness elements, greatly simplifying element replacement operations.
Solution Approach 2:
The patent segments the stiffness adjustment function into two independent parts: a fixed positive stiffness from the beam structure and a movable negative stiffness from the hollow steel plate assembly. This segmentation allows each part to be independently adjusted or replaced, improving operational convenience.
3Manufacturing precision
If a complex structure is used to achieve quasi zero stiffness isolator, then the stiffness can be controlled, but the test period is extended and measurement accuracy is affected by vibration in other directions
Solution Approach 1:
The patent uses a dynamic adjustment mechanism where the hollow steel plate can be quickly repositioned along the beam axis during testing. This dynamic capability allows rapid stiffness adjustment without requiring complex reconfiguration procedures, thereby shortening the test period while maintaining precise stiffness control.
Solution Approach 2:
The hollow steel plate assembly serves multiple functions: it provides negative stiffness, acts as a movable mass, and can be positioned to adjust the overall system stiffness. This multi-functionality reduces the need for additional specialized components, simplifying the structure and reducing test setup time.
4Reliability
If conventional stiffness elements are used, then the isolator can function, but the longitudinal vibration direction cannot be stabilized and vibration in other directions affects test results
Solution Approach 1:
The patent applies local quality enhancement by adding damping blocks at specific locations along the beam where vibration isolation is most needed. These damping elements are strategically placed to provide localized vibration damping in directions other than the longitudinal axis, thereby stabilizing the measurement without affecting the primary longitudinal vibration mode.
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 device enables flexible and accurate adjustment of stiffness values, improving measurement stability and reducing vibration influences, while simplifying the testing process and shortening test duration.
Implementation Method 1
The lead screw is fixed on the bearing pedestal A and the bearing pedestal B through the deep groove ball bearing, and the front end of the lead screw is fixedly connected with the lead screw handwheel through the screws. The moving actuator is penetrated by the lead screw and is matched with the lead screw through the lead screw slider
Implementation Method 2
One end of the spring is fixed on the moving actuator, and the other end is connected with the bolt and fixed by the cooperation between the nut and the bolt. driving the spring to compress or stretch by the left and right movement of the moving actuator, thereby adjusting the negative stiffness value of the overall system
Implementation Method 3
The nut is rotated to move the nut up and down on the supporting rod, thereby squeezing the hollow steel plate and adjusting the bending degree of the hollow steel plate
Implementation Method 4
adjusting the bending degree of the hollow steel plate. Thus, the adjustment of the positive stiffness value of the overall system is completed by changing the stiffness of the steel plate
Implementation Method 5
The lead screw is fixed on the bearing pedestal A and the bearing pedestal B through the deep groove ball bearing
Data Source
AI summary
The present invention provides a test device for a quasi zero stiffness isolator, and belongs to the technical field of vibration response tests of isolators. The device comprises a negative stiffness adjusting mechanism, a positive stiffness adjusting mechanism, and a beam-damping block mechanism. The negative stiffness adjusting mechanism and the positive stiffness adjusting mechanism are connected successively and installed on a beam-mass block system. The test device for the quasi zero stiffness isolator can realize smooth longitudinal vibration of a tested system, and can also flexibly adjust the positive stiffness value and the negative stiffness value of an overall mechanism. The present invention is suitable for a vibration model test of the quasi zero stiffness isolator, and solves the problems of complicated use method, impossibility of flexible adjustment of mechanism stiffness and complicated replacement process of stiffness elements in the device for the existing quasi zero stiffness isolator.