阅读说明：本技术 一种飞机座舱盖安装锁拧紧力矩值的确定方法 (Method for determining tightening torque value of installation lock of aircraft canopy ) 是由 隋福成 解放 刘汉海 于淼 单兴业 于 2021-05-27 设计创作，主要内容包括：本申请提供了一种飞机座舱盖安装拧紧力矩值的确定方法,所述方法包括：第一,根据固定螺栓的直径确定固定螺栓拧紧力矩的范围值；第二,确定试验类型为疲劳试验,试验组至少包含三组不同拧紧力矩的试验件,试验载荷为飞机座舱盖安装锁的最大使用载荷；第三,依据传载路线、边界条件要求构建不同拧紧力矩下的对比试验用的试验件和试验夹具；第四,依据全尺寸飞机结构中的传载路线和边界条件确定试验设备、试验件的支持及加载方式；第五,通过不同拧紧力矩下的对比试验结果得到飞机座舱盖安装锁在不同拧紧力矩下座舱盖安装锁螺栓孔的力学性能影响；第六,根据不同拧紧力矩下座舱盖安装锁螺栓孔的中值寿命最长确定为座舱盖安装锁的最佳拧紧力矩值。(The application provides a method for determining an installation and tightening torque value of an aircraft canopy, which comprises the following steps: firstly, determining a range value of a tightening torque of a fixing bolt according to the diameter of the fixing bolt; secondly, determining the test type as a fatigue test, wherein the test group at least comprises three groups of test pieces with different tightening torques, and the test load is the maximum use load of the aircraft canopy installation lock; thirdly, building test pieces and test clamps for comparison tests under different tightening torques according to the requirements of the load transmission route and the boundary conditions; fourthly, determining support and loading modes of the test equipment and the test piece according to the load transmission route and the boundary conditions in the full-size airplane structure; fifthly, obtaining the mechanical property influence of the installation lock bolt holes of the canopy of the airplane under different tightening torques according to the comparison test results under different tightening torques; and sixthly, determining the longest median service life of the bolt holes of the installation lock of the canopy as the optimal tightening torque value of the installation lock of the canopy according to different tightening torques.)

1. A method for determining a value of an aircraft canopy installation tightening torque, the method comprising:

first, determining the range of tightening torque of the fixing bolt of the aircraft canopy installation lock

Determining a range value of the tightening torque of the fixing bolt according to the diameter of the fixing bolt;

second, determine the type, number and load of the test

Determining the test type as a fatigue test according to the crack initiation life of the bolt hole of the installation lock of the aircraft canopy, wherein the test group at least comprises three groups of test pieces with different tightening torques, and the test load is the maximum use load of the installation lock of the aircraft canopy;

thirdly, constructing a test piece and a test fixture for a contrast test under different tightening torques

Constructing a test piece and a test fixture for a comparison test under different tightening torques according to the requirements of a load transmission path and boundary conditions;

fourthly, determining the support and loading method of the test piece

Determining support and loading modes of test equipment and test pieces according to a load transmission route and boundary conditions in a full-size airplane structure;

fifth, analysis of test results was performed

Obtaining the mechanical property influence of the installation lock bolt holes of the aircraft canopy at different tightening torques according to the comparison test results at different tightening torques;

sixthly, determining an optimum tightening torque value

And determining the longest median life of the bolt holes for installing the lock of the canopy according to different tightening torques as the optimal tightening torque value of the mounting lock of the canopy.

2. A method of determining an aircraft canopy installation tightening torque value according to claim 1, wherein in step one, the range of values of the fixing bolt tightening torque is determined in accordance with a fixing bolt diameter specified in the navigation mark.

3. A method for determining the value of the tightening torque for aircraft canopy installation according to claim 1, wherein in step two, the three test sets comprise the maximum value of the tightening torque, the minimum value of the tightening torque and the median value of the tightening torque.

4. A method for determining an aircraft canopy installation tightening torque value as set forth in claim 3, wherein in step two, the minimum service load of the aircraft canopy installation lock is determined according to the maximum service load and the stress ratio of the aircraft canopy installation lock, thereby obtaining a load spectrum of the aircraft canopy installation lock.

Technical Field

The application belongs to the technical field of aircraft structure maintenance, and particularly relates to a method for determining a tightening torque value of an aircraft canopy installation lock.

Background

The side section bar of the cover of the cabin of a certain type has frequent crack damage in the mounting lock bolt hole in the using process and is analyzed to be fatigue cracking. In the repairing process, in order to inhibit the crack from being initiated, a method of installing a reinforcing piece and reducing the use stress is adopted to increase the initiation period of the crack. The cabin cover side sectional material bears normal concentrated load transmitted by the lock ring, the side sectional material is attached to the lock ring mounting seat, the lock ring mounting seat provides rigidity support for the side sectional material when the side sectional material is actually loaded, the tightness state of the mounting lock fixing bolt directly influences the attaching degree in the using process, and further influences the crack initiation period of the side sectional material lock ring mounting hole.

In view of the above, it is desirable to establish a method for determining the tightening torque value of an aircraft canopy installation lock, in order to prolong the service life of the canopy side profile.

Disclosure of Invention

It is an object of the present application to provide a method of determining a tightening torque value for an aircraft canopy installation lock that addresses or mitigates at least one of the problems of the background art.

The technical scheme of the application is as follows: a method of determining an aircraft canopy installation lock tightening torque value, the method comprising:

first, determining the range of tightening torque of the fixing bolt of the aircraft canopy installation lock

Determining a range value of the tightening torque of the fixing bolt according to the diameter of the fixing bolt;

second, determine the type, number and load of the test

Determining the test type as a fatigue test according to the crack initiation life of the bolt hole of the installation lock of the aircraft canopy, wherein the test group at least comprises three groups of test pieces with different tightening torques, and the test load is the maximum use load of the installation lock of the aircraft canopy;

thirdly, constructing a test piece and a test fixture for a contrast test under different tightening torques

Constructing a test piece and a test fixture for a comparison test under different tightening torques according to the requirements of a load transmission path and boundary conditions;

fourthly, determining the support and loading method of the test piece

Determining support and loading modes of test equipment and test pieces according to a load transmission route and boundary conditions in a full-size airplane structure;

fifth, analysis of test results was performed

Obtaining the mechanical property influence of the installation lock bolt holes of the aircraft canopy at different tightening torques according to the comparison test results at different tightening torques;

sixthly, determining an optimum tightening torque value

And determining the longest median life of the bolt holes for installing the lock of the canopy according to different tightening torques as the optimal tightening torque value of the mounting lock of the canopy.

In the present application, in a first step, the range value of the fixing bolt tightening torque is determined according to the fixing bolt diameter specified in the navigation mark.

In the present application, in step two, the three test sets include the maximum value of the tightening torque, the minimum value of the tightening torque, and the median value of the tightening torque.

In the application, in the second step, the minimum using load of the aircraft canopy installation lock is determined according to the maximum using load and the stress ratio of the aircraft canopy installation lock, so that a load spectrum of the aircraft canopy installation lock is obtained.

The method can more accurately determine the screwing torque of the bolt hole of the installation lock of the aircraft canopy, thereby reducing the time for cracking the bolt hole and prolonging the service life.

Drawings

In order to more clearly illustrate the technical solutions provided by the present application, the following briefly introduces the accompanying drawings. It is to be expressly understood that the drawings described below are only illustrative of some embodiments of the invention.

Fig. 1 is a flowchart of a method for determining a tightening torque value of an aircraft canopy installation lock according to the present application.

Fig. 2 is a schematic view of a test piece and a fixture according to the present application.

Reference numerals

1-side section bar

21-locking ring

22-latch hook

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.

In order to overcome the problem that the bolt hole of the installation lock of the aircraft canopy pointed out in the prior art is easy to crack, the application provides a method for determining the tightening torque value of the installation lock of the aircraft canopy, and the fixing bolt is locked by reasonable tightening torque, so that the probability of cracking of the bolt hole of the installation lock of the aircraft canopy is reduced, and the service life of the bolt hole is prolonged.

As shown in fig. 1, the method for determining the tightening torque value of the aircraft canopy installation lock provided by the present application includes the following steps:

firstly, determining the range value of the tightening torque of the fixing bolt of the canopy installation lock

And determining the range value of the tightening torque of the mounting bolt according to the diameter of the mounting bolt and the navigation mark value.

For example, in one embodiment of the present application, the diameter of the canopy lock anchor bolt is 6mm, and the tightening torque of the anchor bolt determined according to the navigation mark is 670 ± 70N · cm.

Second, test type, number and test load design

In order to determine the crack initiation life, the test type is selected from a fatigue test, and the test load is determined according to the maximum service load.

In order to determine the crack initiation life, the test type selects a fatigue test, the test is divided into three groups, the bolt tightening torque values of test pieces are respectively 600N cm, 670N cm and 740N cm, the number of each group of test pieces is 5, the peak value of a test load spectrum is determined according to the maximum use load, the maximum use load P in the embodiment is_max16000N, stress ratio R0.06, according to maximum load of useStress ratio R resulting in a minimum service load P_min＝R×P_maxThereby determining the test load spectrum.

Thirdly, constructing contrast test pieces and test clamps under different tightening torques

And designing a comparison test piece and a test clamp under different tightening torques according to the requirements of a load transmission path and boundary conditions.

As shown in fig. 2, the side section bar 1 bears the normal concentrated load of the locking ring 21 for installing the aircraft canopy, the structural form of the side section bar 1 is U-shaped according to the requirements of a load transmission route and boundary conditions, the connection form and the size of the side section bar 1 and the locking ring 21 are consistent with those of a full-size canopy, the test fixture comprises a locking ring 21, a locking hook 22 and a clamping steel plate, the test piece and the locking ring 21 are connected through 2M 6 bolts, and the locking hook 22 is hung on the locking ring 21.

Fourthly, determining the support and loading method of the test piece

And selecting test equipment according to the load transmission route and the boundary conditions in the full-size airplane structure, and determining the support and loading method of the test piece.

According to a load transmission route and boundary conditions in a full-size airplane structure (or a side profile), a fatigue testing machine is selected as test loading and supporting equipment, after a test piece and a clamp are assembled, the test piece is connected to the fatigue testing machine through a clamping steel plate and a lock hook 22, and the test piece is subjected to axial Y-shaped tensile force and is positioned in the center of a clamping block of the testing machine during clamping loading.

Fifth, analysis of test results was performed

And analyzing the results of the comparative test under different tightening torques to give the influence of different tightening torques of the installation lock of the canopy on the mechanical property of the structure.

For example, in one embodiment of the present application, when the tightening torque value of the fixing bolt of the test piece is 600N · cm, the corresponding median life of bolt hole crack initiation is 7200 test hours; when the tightening torque value of the fixing bolt is 670N cm, the corresponding median life of the bolt hole crack initiation is 10220 test hours; when the tightening torque value of the fixing bolt is 740N cm, the corresponding median life of the bolt hole crack initiation is 13200 test hours, the tightening torque has obvious influence on the fatigue crack initiation life, and in a given range, the larger the tightening torque is, the longer the crack initiation period is.

Sixthly, determining an optimum tightening torque value

Through comparison tests under different tightening torques, the median life of the bolt hole crack initiation is longest when the tightening torque value is the largest, so that the optimal value of the tightening torque of the fixing bolt of the canopy installation lock is 740N cm.

The method for determining the tightening torque value of the aircraft canopy installation lock can determine the tightening torque of the bolt hole of the aircraft canopy installation lock more accurately, so that the time for cracking of the bolt hole is shortened, and the service life is prolonged.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.