CN-122016211-A - Full-envelope modularized vibration test fixture based on interface boundary simulation

CN122016211ACN 122016211 ACN122016211 ACN 122016211ACN-122016211-A

Abstract

The invention relates to the field of vibration test clamps and discloses a full-envelope modularized vibration test clamp based on interface boundary simulation, which comprises a clamp base and a top cover, wherein the clamp base and the top cover are detachably connected and jointly form an installation cavity, an elastic bag system is arranged in the installation cavity and used for coating and attaching the side surface of a product after filling fluid, the pressure of the fluid in the elastic bag system is adjustable so as to dynamically simulate the distributed boundary pressure acting on the side surface of the product, and a front baffle ring and a rear baffle ring are respectively and adjustably connected to the clamp base and/or the top cover and used for covering and pressing the front end surface and the rear end surface of the product so as to simulate the boundary pressure acting on the end surface of the product. The invention has the beneficial effects that the equivalence of the ground vibration test and the real flight environment in the load transmission path and the structural excitation characteristic is improved.

Inventors

CHEN JIAHAO
MAO YONGJIAN
CHEN SHENGLAI
WAN KUN
YUAN BIAO
JIANG CHENWEI

Assignees

中国工程物理研究院总体工程研究所

Dates

Publication Date: 20260512
Application Date: 20260306

Claims (10)

1. Full-envelope modularized vibration test fixture based on interface boundary simulation, which is characterized by comprising: the clamp base and the top cover are detachably connected and jointly form an installation cavity; The elastic bag system is arranged in the installation cavity and used for coating and attaching the side surface of the product after filling the fluid, and the pressure of the fluid in the elastic bag system can be adjusted so as to dynamically simulate the distribution boundary pressure acting on the side surface of the product; the front baffle ring and the rear baffle ring are respectively and adjustably connected to the clamp base and/or the top cover and used for covering and pressing the front end face and the rear end face of the product so as to simulate the boundary pressure acting on the end faces of the product.
2. The interface boundary simulation-based full envelope modular vibration test fixture of claim 1, wherein the elastic bladder system comprises a bladder made of an elastic material and at least one fluid inlet and outlet tube in communication with the bladder internal cavity, the fluid being a shear thickening fluid that is filled and conditioned through the fluid inlet and outlet tubes.
3. The interface boundary simulation-based full-envelope modular vibration test fixture of claim 2, wherein the elastic bag system comprises a plurality of bags, each bag is provided with an independent fluid chamber and a liquid inlet pipe and a liquid outlet pipe which are communicated with the fluid chamber so as to independently regulate the fluid pressure in each bag.
4. A full-envelope modular vibration testing fixture based on interface boundary simulation as claimed in claim 3, wherein a pressure sensor is provided at the liquid inlet pipe or liquid outlet pipe of at least one of said capsules, said pressure sensor being in communication with a control system for dynamically adjusting said fluid pressure or triggering a safety protection action in accordance with monitored pressure data.
5. The interface boundary simulation-based full-envelope modular vibration test fixture of claim 2, further comprising a stiffness compensation device for compensating for insufficient stiffness of the shear thickening fluid under low frequency vibration, the stiffness compensation device being selected from at least one of a pressurizing unit for increasing initial fluid pressure inside the elastomeric bladder system, an adjustable locking mechanism for adjusting pre-tightening force of the front and/or rear retainer rings against the product end face, and a micro-actuator integrated inside the elastomeric bladder system for actively exciting a fluid stiffness response.
6. The interface boundary simulation-based full-envelope modular vibration test fixture of claim 5, wherein the micro-actuator is disposed within the fluid chamber of the bladder and is configured to apply an active periodic pressure stimulus to the shear thickening fluid to compensate for shear rate deficiencies at low frequency vibrations.
7. The full-envelope modular vibration test fixture based on interface boundary simulation according to claim 2, wherein the liquid inlet pipe and the liquid outlet pipe are metal pipes, one ends of the liquid inlet pipe and the liquid outlet pipe, which are positioned in the inner cavity of the bag body, are provided with reinforced transition parts, the reinforced transition parts are annular plate-shaped, the connection parts of the liquid inlet pipe and the liquid outlet pipe with the bag body are fixed through high-strength adhesive, and the adjacent bag bodies are fixed through high-strength adhesive.
8. The full-envelope modular vibration test fixture based on interface boundary simulation according to claim 1, wherein an elastic piece is arranged between the end face of the rear baffle ring and the corresponding end faces of the fixture base and the top cover, an elastic piece is arranged between the end face of the front baffle ring and the corresponding end faces of the fixture base and the top cover, the rear baffle ring and the corresponding end faces of the front baffle ring and the fixture base and the top cover are connected through connecting bolts, and tightening moments of the corresponding connecting bolts are adjusted to change the pressing force of the front baffle ring and the rear baffle ring on the end faces of products.
9. The full-envelope modular vibration test fixture based on interface boundary simulation according to claim 1, wherein a first cooling flow channel for cooling liquid circulation is arranged inside the fixture base, the first cooling flow channel comprises a first lateral flow channel arranged on two sides of the fixture base, a bottom flow channel and a first top flow channel arranged on the end part of the fixture base, and a first side flow channel liquid inlet pipe and a first side flow channel liquid outlet pipe which are communicated with the first lateral flow channel, and an underflow flow channel liquid inlet pipe and an underflow flow channel liquid outlet pipe which are communicated with the bottom flow channel and the first top flow channel are arranged on the fixture base.
10. The full-envelope modular vibration test fixture based on interface boundary simulation of claim 1, wherein a second cooling flow passage for cooling liquid circulation is arranged inside the top cover, the second cooling flow passage comprises a second lateral flow passage arranged on two sides of the top cover, a second top flow passage and a third top flow passage arranged on the top end of the top cover, a second side flow passage liquid inlet pipe and a second side flow passage liquid outlet pipe which are communicated with the second lateral flow passage, and a top flow passage liquid inlet pipe and a top flow passage liquid outlet pipe which are communicated with the second top flow passage and the third top flow passage are arranged on the top cover.

Description

Full-envelope modularized vibration test fixture based on interface boundary simulation Technical Field The invention relates to the technical field of vibration test clamps, in particular to a full-envelope modularized vibration test clamp based on interface boundary simulation. Background During flight of the aircraft, the outer skin surface is subjected to unevenly distributed, dynamically varying aerodynamic turbulence loads that induce the outer skin to vibrate and further transfer to the internal products. To evaluate the reliability of the product in a real flight environment, such load effects need to be simulated in a ground vibration test. Traditional ground vibration test connects the product with the shaking table through anchor clamps to simulate the transmission of vibration environment. At present, the test fixture is used for carrying out load transmission by connecting a part with higher rigidity in an aircraft, and only can be used for transmitting concentrated load through limited local mounting points on a product. The transmission mode has an essential difference with the boundary condition that the whole surface of the shell bears the distributed aerodynamic load in actual flight, and the spatial distribution, dynamic variability and frequency correlation of the aerodynamic load cannot be simulated. Therefore, the test performed by the traditional clamp is difficult to accurately reproduce the structural vibration response in real flight, and the over test or the under test is easy to cause, so that the equivalence of the ground simulation test and the accuracy of product evaluation are reduced. Disclosure of Invention In order to solve the technical problems, the full-envelope modularized vibration test fixture based on interface boundary simulation is provided, and the equivalence of a ground vibration test and a real flight environment in the load transmission path and the structural excitation characteristics is obviously improved. A full-envelope modularized vibration test fixture based on interface boundary simulation comprises a fixture base and a top cover which are detachably connected and form an installation cavity together, an elastic bag system is arranged in the installation cavity and used for coating and attaching the side surface of a product after filling fluid, the pressure of the fluid in the elastic bag system is adjustable to dynamically simulate the distributed boundary pressure acting on the side surface of the product, and a front baffle ring and a rear baffle ring are respectively and adjustably connected to the fixture base and/or the top cover and used for covering and pressing the front end surface and the rear end surface of the product to simulate the boundary pressure acting on the end surface of the product. The invention has the beneficial effects that the clamp can transfer concentrated load from a traditional local mounting point to full-surface enveloping contact transfer load of a product shell, so that the load acting mode applied to the surface of the product in a test is changed from discrete concentrated force to spatially distributed and dynamically adjustable continuous surface pressure, thereby physically realizing high-fidelity simulation of the distributed unevenly and dynamically variable pneumatic turbulence load boundary conditions borne by an aircraft in actual flight, and remarkably improving the equivalence of a ground vibration test and a real flight environment in load transfer path and structural excitation characteristics. In some embodiments, the elastomeric bladder system includes a bladder made of an elastomeric material, and at least one fluid inlet and outlet tube in communication with the bladder interior cavity, the fluid being a shear thickening fluid that is filled and regulated through the fluid inlet and outlet tube. The elastic bag system is made of elastic materials, and is filled and regulated through the liquid inlet pipe and the liquid outlet pipe, so that the elastic bag system has the function of exceeding the common flexible contact, the characteristic that the apparent viscosity of the shear thickening fluid is increased along with the increase of the external shear rate rather than the characteristic that the apparent viscosity of the shear thickening fluid is obviously increased in a nonlinear way is skillfully utilized, the whole clamp system has the dynamic rigidity with self-adaptive frequency, the fluid is hardened due to the high shear rate under high-frequency vibration, the excitation of a vibration table can be effectively transmitted to a product, the fluid keeps lower rigidity under low-frequency vibration, the overconstrained condition is avoided, and the core defect that the load transmission path in the environment where the product is actually located is irrelevant to the frequency of the load transmission characteristic of the traditional rigid clamp is overcome. In some embodiments, the elast