阅读说明：本技术 飞行器液压管路系统地面模拟试验装置及实验方法 (Aircraft hydraulic pipeline system ground simulation test device and test method ) 是由 刘伟 李树琪 岳珠峰 于 2019-10-24 设计创作，主要内容包括：本发明涉及航空液压管路系统振动试验技术领域,提出一种飞行器液压管路系统地面模拟试验装置及实验方法,该飞行器液压管路系统地面模拟试验装置包括：模拟器件、液压管路、振动组件以及液压源。模拟器件用于模拟支撑所述液压管路的飞行器部件；液压管路固定连接于所述模拟器件；振动组件连接于所述模拟器件,用于向所述模拟器件施加振动激励；液压源用于向所述液压管路输入预设参数的液压脉动。本公开能够在地面模拟飞行器自身振动以及液压管道中液压脉动对液压管道自身振动状态以及应变的影响。(The invention relates to the technical field of vibration tests of aviation hydraulic pipeline systems, and provides a ground simulation test device and a ground simulation test method for an aircraft hydraulic pipeline system, wherein the ground simulation test device for the aircraft hydraulic pipeline system comprises: the device comprises an analog device, a hydraulic pipeline, a vibration assembly and a hydraulic source. The simulation device is used for simulating an aircraft part supporting the hydraulic pipeline; the hydraulic pipeline is fixedly connected with the analog device; the vibration assembly is connected to the simulation device and used for applying vibration excitation to the simulation device; and the hydraulic source is used for inputting hydraulic pulsation with preset parameters to the hydraulic pipeline. The method and the device can simulate the self vibration of the aircraft and the influence of hydraulic pulsation in the hydraulic pipeline on the self vibration state and strain of the hydraulic pipeline on the ground.)

1. The utility model provides an aircraft hydraulic pressure pipe-line system ground analogue test device which characterized in that includes:

simulation means for simulating an aircraft component supporting the hydraulic circuit;

the hydraulic pipeline is fixedly connected to the analog device;

the vibration assembly is connected to the simulation device and is used for applying vibration excitation to the simulation device;

and the hydraulic source is used for inputting hydraulic pulsation with preset parameters to the hydraulic pipeline.

2. The aircraft hydraulic line system ground simulation test device of claim 1, wherein the hydraulic line is an arresting hook hydraulic line secured to an outer barrel of an engine of the aircraft and a plurality of belly ribs, the simulation means comprising:

a support table;

the barrel structure is fixedly connected to the support table and used for simulating the outer cylinder of the engine of the aircraft;

and the rib plate structures are connected to the support table and used for simulating the ventral rib beam of the aircraft.

3. The aircraft hydraulic line system ground simulation test device of claim 2, wherein the arresting hook hydraulic line is fixedly connected to the plurality of rib plate structures by a clamp.

4. The aircraft hydraulic line system ground simulation test device of claim 2, wherein the arresting hook hydraulic line is fixedly connected to the drum structure by a clamp.

5. The aircraft hydraulic line system ground simulation test device of claim 2, wherein the vibration assembly comprises:

the vibration exciter is fixed on the rib plate structure and is used for applying vibration excitation to the rib plate structure;

and the vibration table is fixedly connected with the drum structure and is used for applying vibration excitation to the drum structure.

6. The aircraft hydraulic pipeline system ground simulation test device of claim 2, wherein the support platform is provided with a sliding groove extending along the extension direction of the arresting hook hydraulic pipeline, and the rib plate structure is slidably connected in the sliding groove.

7. The aircraft hydraulic line system ground simulation test device according to any one of claims 1 to 6, further comprising:

the strain gauge is arranged on the hydraulic pipeline and used for detecting the strain of the hydraulic pipeline;

and the acceleration sensor is arranged on the hydraulic pipeline and used for detecting the vibration acceleration of the hydraulic pipeline.

8. The aircraft hydraulic line system ground simulation test device of claim 2, further comprising:

and the arresting hook is fixedly connected to the hydraulic pipeline.

9. A ground simulation test method for an aircraft hydraulic pipeline system, which applies the ground simulation test device for the aircraft hydraulic pipeline system of any one of claims 1 to 8, and is characterized by comprising the following steps:

inputting hydraulic pulsation under different working conditions to the hydraulic pipeline by using the hydraulic source, wherein the working conditions of the hydraulic pulsation comprise a hydraulic system, a pulsation frequency and a pulsation amplitude of the hydraulic pulsation;

and detecting response states of the strain and the acceleration at the preset position of the hydraulic pipeline.

10. A ground simulation test method for an aircraft hydraulic pipeline system, which applies the ground simulation test device for the aircraft hydraulic pipeline system of any one of claims 1 to 8, and is characterized by comprising the following steps:

applying different vibration excitations to preset positions of the hydraulic pipeline by using a vibration assembly;

and detecting the response state of the maximum stress of the hydraulic pipeline.

Technical Field

The invention relates to the technical field of vibration tests of aviation hydraulic pipeline systems, in particular to a ground simulation test device and a ground simulation test method for an aircraft hydraulic pipeline system.

Background

The structural characteristics and the service environment of the hydraulic pipeline of the aircraft are very special. The aircraft hydraulic pipeline has the characteristics of limited installation space and weak support. The laying arrangement of the aircraft hydraulic pipeline is unfolded on the existing machine body structure, and at the moment, the laying arrangement is limited by various factors such as aviation structural integrity or unreserved installation space, so that the aviation pipeline needs to be bent in actual engineering or a hoop cannot be arranged at a theoretical optimal position sometimes, namely the installation space is limited. In addition, aircraft hydraulic lines also feature "weak support", which means that the body structures, connector clips, etc. to which the lines are attached have a weak support stiffness, which is different from full restraint and weak support stiffness for the lines. The weak support is mainly embodied by: on one hand, the light aircraft body is mostly a thin-wall shell structure (such as a casing and a rib frame structure), a hoop and an auxiliary support structure.

On the other hand, the body structure of the aircraft inevitably deforms or vibrates and displaces (the deformation of the high aspect ratio wing is larger) in the service process of the aircraft, so that the supporting rigidity of the pipeline system is further weakened. This "limited location" and "weak bearing stiffness" characteristic of an aircraft piping system can cause undesirable changes in the dynamics of the piping system under the original design. Not only influences the fixing and frequency modulation effects of the aviation pipeline system, but also causes the stress state change of the pipeline-hoop, easily causes the resonance failure of the pipeline system and weakens the dynamic quality of the whole pipeline system. Therefore, it is necessary to provide an experimental device for performing simulation tests on the vibration characteristics and the stress characteristics of the hydraulic pipeline of the aircraft.

It is to be noted that the information invented in the above background section is only for enhancing the understanding of the background of the present invention, and therefore, may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The invention aims to provide a ground simulation test device and a ground simulation test method for an aircraft hydraulic pipeline system, so as to accurately test and analyze the vibration characteristic and the stress characteristic of an aircraft hydraulic pipeline.

Additional features and advantages of the invention will be set forth in the detailed description which follows, or may be learned by practice of the invention.

According to an aspect of the present disclosure, there is provided an aircraft hydraulic line system ground simulation test apparatus, including: analog device, hydraulic pressure pipeline, vibration subassembly, hydraulic pressure source. The simulation device is used for simulating an aircraft part supporting the hydraulic pipeline; the hydraulic pipeline is fixedly connected with the analog device; the vibration assembly is connected to the simulation device and used for applying vibration excitation to the simulation device; and the hydraulic source is used for inputting hydraulic pulsation with preset parameters to the hydraulic pipeline.

In an exemplary embodiment of the present disclosure, the hydraulic line is a barrier hook hydraulic line fixed to an outer engine cylinder of the aircraft and a plurality of ventral ribs, and the simulation device includes a support table, a drum structure, and a plurality of rib plate structures. The barrel structure is fixedly connected to the support table and used for simulating the outer cylinder of the engine of the aircraft; a plurality of rib structures are connected to the support table for simulating a belly rib of the aircraft.

In an exemplary embodiment of the disclosure, the arresting hook hydraulic line is fixedly connected to the plurality of rib plate structures by a clamp.

In an exemplary embodiment of the present disclosure, the arresting hook hydraulic line is fixedly connected to the drum structure by a clamp band through a clamp band.

In an exemplary embodiment of the present disclosure, the vibration assembly includes a vibration exciter and a vibration table. The vibration exciter is fixed on the rib plate structure and used for applying vibration excitation to the rib plate structure; the vibration table is fixedly connected with the drum structure and is used for applying vibration excitation to the drum structure.

In an exemplary embodiment of the disclosure, the support platform is provided with a sliding groove extending along an extending direction of the arresting hook hydraulic pipeline, and the rib plate structure is slidably connected in the sliding groove.

In an exemplary embodiment of the disclosure, the aircraft hydraulic pipeline system ground simulation test device further includes a strain gauge and an acceleration sensor. The strain gauge is arranged on the hydraulic pipeline and used for detecting the strain of the hydraulic pipeline; the acceleration sensor is arranged on the hydraulic pipeline and used for detecting the vibration acceleration of the hydraulic pipeline.

In an exemplary embodiment of the disclosure, the aircraft hydraulic pipeline system ground simulation test device further includes an arresting hook, and the arresting hook is fixedly connected to the hydraulic pipeline.

According to one aspect of the disclosure, a ground simulation test method for an aircraft hydraulic pipeline system is provided, wherein the ground simulation test device for the aircraft hydraulic pipeline system is applied, and the method comprises the following steps:

inputting hydraulic pulsation under different working conditions to the hydraulic pipeline by using the hydraulic source, wherein the working conditions of the hydraulic pulsation comprise a hydraulic system, a pulsation frequency and a pulsation amplitude of the hydraulic pulsation;

and detecting response states of the strain and the acceleration at the preset position of the hydraulic pipeline.

According to one aspect of the disclosure, a ground simulation test method for an aircraft hydraulic pipeline system is provided, wherein the ground simulation test device for the aircraft hydraulic pipeline system is applied, and the method comprises the following steps:

applying different vibration excitations to preset positions of the hydraulic pipeline by using a vibration assembly;

and detecting the response state of the maximum stress of the hydraulic pipeline.

The utility model provides an aircraft hydraulic pressure pipe-line system ground analogue test device, this aircraft hydraulic pressure pipe-line system ground analogue test device includes: the device comprises an analog device, a hydraulic pipeline, a vibration component and a hydraulic source. The simulation device is used for simulating an aircraft part supporting the hydraulic pipeline; the hydraulic pipeline is fixedly connected with the analog device; the vibration assembly is connected to the simulation device and used for applying vibration excitation to the simulation device; and the hydraulic source is used for inputting hydraulic pulsation with preset parameters to the hydraulic pipeline. The aircraft hydraulic pipeline system ground simulation test device provided by the disclosure simulates the vibration excitation of the body vibration to the hydraulic pipeline when the aircraft flies through the vibration component, and simulates the hydraulic pulse in the hydraulic pipeline through the hydraulic source, so that the influence of the body vibration factor and the hydraulic pulsation factor in the hydraulic pipeline on the stress and vibration of the hydraulic pipeline in the actual flying state of the aircraft can be simulated.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic structural diagram of an exemplary embodiment of a ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the present disclosure;

FIG. 2 is a schematic structural diagram of a vibration assembly in an exemplary embodiment of a ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the present disclosure;

FIG. 3 is a schematic structural diagram of a support table in an exemplary embodiment of a ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the disclosure;

FIG. 4 is a schematic structural diagram of a hydraulic source in an exemplary embodiment of a ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the present disclosure;

FIG. 5 is a schematic structural view of a section of hydraulic piping on a drum structure;

FIG. 6 is a schematic diagram of the hydraulic circuit of FIG. 5;

FIG. 7 is a strain fluctuation analysis chart of a strain observation point 1 under different hydraulic systems;

FIG. 8 is a pipeline axial and circumferential strain fluctuation analysis diagram of a strain observation point 1 under different hydraulic systems;

FIG. 9 is an acceleration response analysis chart of a hydraulic pipeline under different hydraulic systems;

FIG. 10 is a view showing an initial position of a clamp on a hydraulic line of the arresting hook;

FIG. 11 is a diagram of the distribution of acceleration sensors on a hydraulic line;

FIG. 12 is a diagram showing how strain gauges are arranged;

FIG. 13 is a graph of stress changes for different strain gages;

FIG. 14 is a graph of a plurality of moveable clamp natural frequencies and vibrational response sensitivity analysis;

FIG. 15 is a graph showing the relationship between the clamp adjustment amount and the vibration stress of the hydraulic pipe.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". Other relative terms, such as "high," "low," "top," "bottom," "left," "right," and the like are also intended to have similar meanings. When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," and the like are used to denote the presence of one or more elements/components/parts; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.

The present exemplary embodiment first provides an aircraft hydraulic line system ground simulation test apparatus, which includes: analog device, hydraulic pressure pipeline, vibration subassembly, hydraulic pressure source. The simulation device is used for simulating an aircraft part supporting the hydraulic pipeline; the hydraulic pipeline is fixedly connected with the analog device; the vibration assembly is connected to the simulation device and used for applying vibration excitation to the simulation device; and the hydraulic source is used for inputting hydraulic pulsation with preset parameters to the hydraulic pipeline.

The utility model provides an aircraft hydraulic pressure pipe-line system ground analogue test device, this aircraft hydraulic pressure pipe-line system ground analogue test device includes: analog device, hydraulic pressure pipeline, vibration subassembly, hydraulic pressure source. The simulation device is used for simulating an aircraft part supporting the hydraulic pipeline; the hydraulic pipeline is fixedly connected with the analog device; the vibration assembly is connected to the simulation device and used for applying vibration excitation to the simulation device; and the hydraulic source is used for inputting hydraulic pulsation with preset parameters to the hydraulic pipeline. The aircraft hydraulic pipeline system ground simulation test device provided by the disclosure simulates the vibration excitation of the body vibration to the hydraulic pipeline when the aircraft flies through the vibration component, and simulates the hydraulic pulse in the hydraulic pipeline through the hydraulic source, so that the influence of the body vibration factor and the hydraulic pulsation factor in the hydraulic pipeline on the stress and vibration of the hydraulic pipeline in the actual flying state of the aircraft can be simulated.

In the present exemplary embodiment, the hydraulic pipeline is a barrier hook hydraulic pipeline, and the barrier hook hydraulic pipeline is fixed to an outer cylinder of an engine of the aircraft and a plurality of ventral ribs, as shown in fig. 1, which is a schematic structural diagram of an exemplary embodiment of the ground simulation test apparatus of the aircraft hydraulic pipeline system of the present disclosure. The simulation device can comprise a support table 1, a barrel structure 2, a plurality of rib plate structures 3, and a barrel structure 2 which is fixedly connected to the support table 1 and used for simulating the outer cylinder of the engine of the aircraft; a plurality of ribs 3 are structurally connected to the support table 1 for simulating the ventral ribs of the aircraft.

Because the support of aircraft hydraulic circuit is "weak support", therefore, as shown in fig. 1, arresting hook hydraulic circuit 5 can be through clamp 9 fixed connection in a plurality of on the floor structure, arresting hook hydraulic circuit 5 can the clamp through lug 4 fixed connection in on the drum structure 2 to realize the "weak support" structure of simulation hydraulic circuit at the engine urceolus, and a plurality of ventral rib roof beam. Wherein the lug 4 is used for fixing the joint of the hydraulic pipeline 5 of the arresting hook.

In the present exemplary embodiment, as shown in fig. 2, a schematic structural diagram of a vibration component in an exemplary embodiment of the ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the present disclosure is shown. The vibration assembly may comprise a vibration exciter 6, a vibration table (not shown). The vibration exciter 6 is fixed on the rib plate structure 3 and is used for applying vibration excitation to the rib plate structure 3; the vibration table is fixedly connected with the barrel structure 2 and used for applying vibration excitation to the barrel structure so as to simulate the vibration of the aircraft body during flight. The vibration exciter 6 may include a top rod 61 for piston movement, and the top rod 61 may be vertically connected to the rib plate structure 3 through the fixing member 7. As shown in fig. 1, the aircraft hydraulic pipeline system ground simulation test device may further include a turntable 8, the turntable 8 is connected to the bottom of the drum structure 2, and the vibration table may be disposed at the bottom of the turntable 8, so as to provide vibration excitation to the drum structure 2.

In the actual support structure of the hydraulic lines of an aircraft, the clips can only be arranged on the rib, and when the installation space of the hydraulic lines is limited, the common practice is to change the clipping position of the clips on the hydraulic lines. In the present exemplary embodiment, as shown in fig. 3, a schematic structural diagram of a support table in an exemplary embodiment of the ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the present disclosure is shown. The supporting table 1 is provided with a sliding groove 10 extending along the extension direction of the arresting hook hydraulic pipeline 5, and the rib plate structure 3 is connected in the sliding groove 10 in a sliding mode. The rib structure 3 can slide in the sliding groove 10, so that different clamping positions of the clamp on a hydraulic pipeline are simulated.

In the present exemplary embodiment, as shown in fig. 4, a schematic structural diagram of a hydraulic source in an exemplary embodiment of the ground simulation test apparatus for a hydraulic pipeline system of an aircraft according to the present disclosure is shown. The hydraulic source 12 may be an oil truck, and the hydraulic source 12 is communicated with an inlet end of a hydraulic oil path and is configured to input hydraulic pulsation of a preset parameter to a hydraulic pipeline.

In this exemplary embodiment, the aircraft hydraulic pipeline system ground simulation test device further includes a strain gauge and an acceleration sensor. The strain gauge is arranged on the hydraulic pipeline and used for detecting the strain of the hydraulic pipeline; the acceleration sensor is arranged on the hydraulic pipeline and used for detecting the vibration acceleration of the hydraulic pipeline. The strain and vibration states of the hydraulic pipeline can be checked through the strain gauge, the acceleration sensor and other conventional supporting facilities.

In the exemplary embodiment, as shown in fig. 1, the ground simulation test device for the hydraulic line system of the crawler further comprises an arresting hook 11, and the arresting hook 11 is fixedly connected to the tail end of the hydraulic line 5. The arrangement of the arresting hook 11 enables the actual state of the hydraulic line to be simulated more accurately.

The present exemplary embodiment further provides an aircraft hydraulic pipeline system ground simulation test method, in which the aircraft hydraulic pipeline system ground simulation test apparatus is applied, and the method includes:

inputting hydraulic pulsation under different working conditions to the hydraulic pipeline by using the hydraulic source, wherein the working conditions of the hydraulic pulsation comprise a hydraulic system, a pulsation frequency and a pulsation amplitude of the hydraulic pulsation;

and detecting response states of the strain and the acceleration at the preset position of the hydraulic pipeline.

The simulation test method is exemplified below:

the test method can be selectively implemented on the whole hydraulic pipeline or one local hydraulic pipeline. The test method provided by the exemplary embodiment is performed on a local hydraulic line on the drum structure. Fig. 5 is a schematic structural diagram of a section of hydraulic pipeline on a drum structure.

Fig. 6 is a schematic diagram of the hydraulic circuit of fig. 5. Five dynamic response observation points are arranged on the section of hydraulic pipeline, wherein the five dynamic response observation points comprise three strain observation points and two acceleration response observation points. The strain observation point is provided with a strain gauge, and the acceleration response observation point is provided with an acceleration sensor. Wherein, strain observation point 1 and strain observation point 2 pay attention to the strain of hydraulic line circumference and axial, and strain observation point 3 pays attention to the axial strain of hydraulic line. Acceleration responsive observation points 1 are located between the clips 13 and acceleration responsive observation points 2 are located at the base of the clips 13. According to the sampling theorem, the sampling frequency of the acceleration sensor should be selected to be greater than twice the frequency of the pressure pulsation emitted by the hydraulic pressure source.

The hydraulic source can apply hydraulic pulsation with preset parameters to the hydraulic pipeline, and the hydraulic pipeline can be subjected to strain and vibration state tests under the hydraulic pulsation with different parameters. The parameters of the hydraulic pulsation may include a waveform of the hydraulic pulsation, a hydraulic system, a pulsation amplitude, and a pulsation frequency. In the present exemplary embodiment, the waveform of the hydraulic pulsation may be a sine wave; the hydraulic system can be 21Mpa, 28Mpa and 35Mpa, and the pulsation amplitude can be +/-5%, +/-7.5% and +/-10%; the pulsation frequency may be 5Hz, 10Hz, 15 Hz.

In the exemplary embodiment, the dynamic strain data of the strain observation point 1 is used for analyzing the influence of the hydraulic pulsation parameters of the hydraulic pipeline on the strain fluctuation of the hydraulic pipeline structure, the specific numerical value measured in the test is micro-strain (mu epsilon), and the conversion relation of the micro-strain and the strain epsilon is that epsilon is 10 ⁶Mu epsilon. During the test, the 'return-to-zero' operation of the strain gauge is carried out under the static pressure state of the working condition corresponding to the hydraulic system, namely, the strain of the pipeline under the static pressure state corresponding to the hydraulic system is set to be 0. The value of the dynamic strain measured by the test is not the real strain of the pipeline, but the fluctuation value of the strain of the pipeline under the static pressure state. And analyzing the acceleration response characteristic of the pipeline system through the acceleration response between the two hoops and the root parts of the hoops, wherein the acceleration unit is g. By this test it is possible to obtain: (1) the dynamic strain response rule of the pipeline under different rated hydraulic systems; (2) the dynamic strain response rule of the pipeline under different hydraulic pulsation amplitudes; (3) and (3) a pipeline dynamic strain response rule under different hydraulic pulsation frequencies. The embodiment only demonstrates the test results of the dynamic strain and acceleration response law of the hydraulic pipeline under different rated hydraulic systems.

As shown in fig. 7, a strain fluctuation analysis chart of the strain observation point 1 under different hydraulic systems is shown. FIG. 7 shows the comparison of the circumferential strain fluctuation of the hydraulic pipeline under the action of 21MPa/28MPa/35MPa of different hydraulic systems when the pulsation amplitude is +/-5% and the pulsation frequency is 5 Hz. The single peak value of the strain fluctuation of the pipeline at 21MPa is 17, the single peak value of the strain fluctuation of 28MPa is 24, which is increased by 29 percent relative to 21MPa, and the single peak value of the strain fluctuation of the pipeline at 35MPa is 29, which is increased by 71 percent relative to 21 MPa.

As shown in fig. 8, a pipeline axial and circumferential strain fluctuation analysis chart of the strain observation point 1 under different hydraulic systems is shown. FIG. 8 shows that when the pulsation amplitude is +/-5% and the pulsation frequency is 5Hz, the axial and circumferential dynamic strain fluctuations of the hydraulic pipeline system strain observation point 1 are compared under the action of the 21MPa/28MPa/35MPa hydraulic pulsation of three different hydraulic systems. The circumferential strain fluctuation peak value of the pipeline is far larger than the axial strain fluctuation peak value under the action of 21MPa/28MPa/35MPa of the three hydraulic systems. The peak of the circumferential strain fluctuation is 3.8, 3.4, 2.9 times the peak of the axial strain. The influence of the hydraulic system change on the axial strain fluctuation peak value is larger than that of the circumferential strain fluctuation peak value.

Fig. 9 is a diagram showing an analysis of the acceleration response of the hydraulic pipeline under different hydraulic systems. As can be seen from FIG. 9, the maximum acceleration response operating condition is 35MPa- +/-10% -15Hz, the peak response value of the acceleration observation point 1 reaches 0.58g, and the peak response value of the acceleration observation point 1 is 0.28 g.

Table 1 shows acceleration responses of two acceleration observation points under different rated hydraulic systems and working conditions thereof, and it can be found that the acceleration peak value of the middle pipeline part of the two hoops is twice of the acceleration peak value of the root part of the hoops, and the conclusion also holds under other working conditions.

TABLE 1 comparison of acceleration peak values (unit/g) of various measuring points under different working conditions

The present exemplary embodiment further provides an aircraft hydraulic pipeline system ground simulation test method, in which the aircraft hydraulic pipeline system ground simulation test apparatus is applied, and the method includes:

applying different vibration excitations to preset positions of the hydraulic pipeline by using a vibration assembly;

and detecting the response state of the maximum stress of the hydraulic pipeline.

The simulation test method is exemplified below:

to demonstrate the experimental method, the present exemplary embodiment employs an 8mm dual hole clamp and a pipe diameter model. The response test method of the arresting hook hydraulic pipeline system under the vibration condition and the hoop position optimization design test verification method are researched.

First, the present exemplary embodiment establishes a hoop initial position state model, which is a hoop initial position state diagram on the arresting hook hydraulic pipe, as shown in fig. 10. The clips are numbered a-F in sequence, with clips a and E being fixed restraint, and the remaining clips B, C, D, F being movable with the ribs in the direction of the pipeline. As shown in table 2, 9 different band position constraints were determined. Wherein Xb and Xf are the clamp that needs the removal, and when the clamp was located the slot intermediate position, its coordinate was 0, and its coordinate positive direction increases when the clamp moved left, and when the clamp moved right, its coordinate negative direction grow.

TABLE 2 initial position coordinates of the clamp (unit: cm)

Then, the present exemplary embodiment arranges acceleration sensors on the pipeline between every two clamps, as shown in fig. 11, which is a distribution diagram of the acceleration sensors on the hydraulic pipeline, and 5 acceleration sensors are distributed on the hydraulic pipeline in total, and are respectively marked as 1-5.

The exemplary embodiment then uses a hammer mode test to test the modal parameters of the piping system at different locations of the clamp. The force hammer is used for applying primary excitation, an acceleration sensor arranged on the pipeline transmits a signal to a data acquisition instrument, and a computer is used for displaying a frequency response curve of the pipeline by adopting Fast Fourier Transform (FFT). Results of modal testing of the initial position and other positions of the clip are shown in table 3.

TABLE 3 resonance frequency of pipe system with different positions of hoop

The root of the hydraulic pipeline is provided with a resistance strain gauge which can sense real-time strain and transmit a signal to an acquisition instrument, and a computer can display a strain-time curve and calculate the stress according to the relation sigma of the stress and the strain, namely E epsilon. As shown in fig. 12, which is a diagram of the arrangement mode of the strain gauge, 1, 2, 3, 4 represent the strain gauge, the strain gauge 1, 2, 3, 4 is arranged at a position 5mm away from the tail end of the hydraulic pipeline, the strain gauge 1, 2 is arranged on the upper hydraulic pipeline, and the strain gauge 1, 2 is spaced by 90 degrees in the circumferential direction of the upper hydraulic pipeline; the strain gauges 3, 4 are provided on the lower hydraulic line, and the strain gauges 3, 4 are spaced 90 degrees apart in the circumferential direction of the lower hydraulic line.

Then, an external excitation can be applied to the hydraulic pipeline through the vibration exciter so as to detect the strain state of the hydraulic pipeline under different position states of the hoop. For example, when the clamps are located at the 0-coordinate position, the vibration frequency of the vibration exciter can be 300Hz, the displacement peak value is 0.08mm, and the stay time is 30s, so that external excitation is applied to the rib plate structure at the clamp of the hydraulic pipeline E of the arresting hook. Fig. 13 shows a stress variation diagram of different strain gauges. As can be seen from FIG. 13, the maximum stress was 2.75MPa at the strain gage No. 1 position.

The exemplary embodiment may also be implemented by introducing the arresting hook piping system into finite element analysis software to analyze the natural frequency and vibration response sensitivity at the natural frequency of 300Hz for the B, C, D, F four band positions, as shown in fig. 14, which is a plurality of moveable band natural frequency and vibration response sensitivity analysis plots. The main index is the natural frequency, the total index is the maximum stress of the hydraulic pipeline vibration, and the result shows that the positions of the clamps E and F have great influence on the response index of the pipeline system.

The exemplary embodiment may also optimize the clamp position using a multi-objective genetic algorithm to minimize the vibrational stress of the hydraulic piping system, and similarly, apply an external excitation to the rib structure at the E-clamp for excitation using the same frequency of 300Hz, a displacement peak of 0.08mm, and a dwell of 30 s. Fig. 15 is a graph showing a change in the relationship between the clamp adjustment amount and the hydraulic pipe vibration stress. The results show that the vibration stress of the hydraulic pipe is minimal after moving the clamp F4.5 cm to the left. The maximum stress of the pipeline system before and after optimization is compared with that of the pipeline system in table 4, and after the hoop layout is optimized, the maximum stress of the pipeline system structure at a specified frequency is reduced by more than 10%.

TABLE 4 Clamp position optimization front and rear maximum stress test results

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the terms of the appended claims.