Variable Stiffness Damper Assembly for Rotor Vibration Control
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Solution Overview
Problem
Mechanical structures, such as those in turbine engines, often have limited stiffness properties, which restrict their operational range and lead to issues like unbalance, vibrations, and damage during high-stress conditions.
Innovation Solution
A variable stiffness damper system is introduced, featuring an inner spring and an outer spring with selectively couplable bumpers, allowing for adaptive stiffness adjustment based on load conditions, enabling energy absorption through elastic buckling and improved damping capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single linear stiffness structural member is used, then the structure is simple and easy to manufacture, but the operational range is limited and cannot adapt to varying load conditions
Solution Approach 1:
The damper system is divided into multiple independent spring elements (first spring, second spring, third spring) arranged in parallel, each contributing to the overall stiffness. This segmentation allows the system to achieve variable stiffness characteristics by selectively engaging different spring combinations based on load conditions, resolving the contradiction between adaptability and complexity.
Solution Approach 2:
The damper system transitions from a static single-stiffness structure to a dynamic multi-stiffness system where the effective stiffness changes based on applied load. The nonlinear force-deflection behavior emerges from the interaction between multiple springs and bumpers, enabling the structure to adapt its stiffness characteristics dynamically to varying operational conditions.
2Stability of the object's composition
If linear stiffness structural members are used, then the design is simple, but the range of operability relative to load or deflection behaviors is limited
Solution Approach 1:
The damper system employs a composite structural approach by combining multiple spring elements with different stiffness characteristics (first spring with stiffness k1, second spring with stiffness k2, third spring with stiffness k3) along with bumper elements. This composite configuration creates a nonlinear force-deflection relationship that provides both stability across a wide load range and adaptability to varying operational conditions.
3Adaptability or versatility
If multiple spring elements and bumpers are added to achieve variable stiffness, then stiffness adaptability is improved, but the device complexity increases
Solution Approach 1:
The damper system arranges spring elements and bumper elements in a nested configuration where the first spring, second spring, and third spring are positioned adjacent to and interact with each other within a confined space. The bumpers are strategically positioned to selectively engage with different spring elements, creating a compact integrated assembly that achieves variable stiffness functionality without excessive complexity.
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 system reduces rotor dynamic responses, mitigates damage from unbalance and eccentricities, enhances stability, and reduces non-synchronous vibrations and noise, leading to improved efficiency and reduced maintenance needs in turbine engines.
Implementation Method 1
allows for adaptive stiffness adjustment based on load conditions, enabling energy absorption through elastic buckling
Implementation Method 2
improved damping capabilities
Data Source
AI summary
A variable stiffness damper system including an inner spring positioned between a first wall and a second wall, in which the inner spring includes a first member and a second member each coupled together at a distal end by an inner bumper. The first member and the second member are each contoured toward one another. The first member, the second member, and the inner bumper form a cavity therebetween. An outer spring is positioned between the inner spring and the first wall or the second wall. The outer spring includes a spring arm contoured toward the inner spring. The outer spring includes an outer bumper positioned between the inner bumper and the first wall or the second wall. The inner bumper and the outer bumper are selectively couplable to one another based on a load applied to the damper system.