CN110135044B - Method for calculating test load of aircraft fuselage curved plate - Google Patents
Method for calculating test load of aircraft fuselage curved plate Download PDFInfo
- Publication number
- CN110135044B CN110135044B CN201910384399.0A CN201910384399A CN110135044B CN 110135044 B CN110135044 B CN 110135044B CN 201910384399 A CN201910384399 A CN 201910384399A CN 110135044 B CN110135044 B CN 110135044B
- Authority
- CN
- China
- Prior art keywords
- strain
- load
- reference load
- positive
- matrix
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/15—Vehicle, aircraft or watercraft design
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/06—Power analysis or power optimisation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Engineering & Computer Science (AREA)
- Evolutionary Computation (AREA)
- Aviation & Aerospace Engineering (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Mathematical Analysis (AREA)
- Computational Mathematics (AREA)
- Automation & Control Theory (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention provides a load calculation method for a structural strength test of a curved plate of an aircraft body, which is characterized in that a strain result of the curved plate in a full-load loading state and a strain result of the curved plate in various reference test loads are calculated by means of a finite element method, a strain error matrix is constructed on the basis of the strain error matrix, and each load coefficient is calculated by means of a multidimensional extremum problem solving method, so that the load which should be applied in the curved plate test can be calculated quickly, and a better engineering application effect is achieved.
Description
Technical Field
The invention relates to the field of aircraft fuselage structural strength test, in particular to a load calculation method for an aircraft fuselage bent plate structural strength test.
Background
When an aircraft panel test is carried out, boundary loads which are required to be applied in the test are generally required to be determined firstly, but for a relatively complex body curved panel test piece, the boundary loads are relatively difficult to calculate, and the problem of calculating the test loads of the body curved panel is solved by combining a finite element method with a mathematical optimization algorithm.
Disclosure of Invention
The invention aims to:
the calculation method of the bending test load can rapidly and accurately calculate the test load which should be applied in the bending test, and support is provided for smooth development of the bending test.
The technical scheme is as follows: a method for calculating the load of a curve plate test comprises the following steps:
(1) Selecting a target area from the overall model, and generating a target strain matrix;
(2) Establishing finite element models of a curved plate and a related test fixture, respectively applying various reference loads, calculating structural strain responses under the various reference loads, and generating corresponding reference load strain matrixes;
(3) Multiplying each reference load strain matrix by different load coefficients, and superposing to form a combined strain matrix;
(4) Subtracting the combined strain matrix from the target strain matrix to form an error strain matrix;
(5) Forming an objective function F (lambda) for calculating a load factor;
(6) And calculating the load coefficient vector lambda of each reference load by using a multidimensional extremum solving method with the minimum value of the function F (lambda) as a target, namely solving: min F (lambda), lambda E R n 。
The beneficial effects are that:
when the strength test of the body bent plate is carried out, the loaded state of the bent plate on the test fixture is ensured to be consistent with the loaded state of the bent plate in the whole machine, so that the boundary load of the bent plate test piece in the test needs to be determined, but the boundary load of the bent plate is complex and is difficult to calculate by a theoretical method. The invention calculates the strain result of the curved plate in the full-load loading state by means of the finite element method, and the strain result in various reference test loads, constructs a strain error matrix, and calculates each load coefficient by means of the multidimensional extremum problem solving method based on the strain error matrix, so that the load which should be applied in the curved plate test can be calculated quickly, and the invention has better engineering application effect.
Drawings
FIG. 1 is a schematic diagram of a target area curved plate test piece in an overall model.
FIG. 2 is a finite element model including a curved plate test piece and an associated test fixture.
Fig. 3 is a strain cloud of a curved plate in a full machine model.
Fig. 4 is a strain cloud of the curved plate in the test jig model.
Fig. 5 is a schematic view of various loads experienced by a curved plate.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings.
A method for calculating the load of a curve plate test comprises the following steps:
(1) Selecting a curved plate to be tested from the overall model as a target area, and generating a target strain matrix;
as shown in FIG. 1, FIG. 1 is a finite element model of the whole fuselage, the region in the box is the target region, and the target is output according to the existing whole-machine strain calculation resultThe strain value of each finite element in the region and a target strain matrix A is generated * ：
Wherein:
positive strain in the X direction for the nth cell within the target region; />
Positive strain in the Y direction for the nth cell within the target region; />
Is the shear strain of the nth cell within the target region.
(2) Establishing finite element models of a curved plate and a related test fixture, respectively applying various reference loads, calculating structural strain response under the independent action of the various reference loads, and generating a corresponding reference load strain matrix;
FIG. 2 is a finite element model of a curved plate containing test fixtures, each applying various reference loads including axle load, bending load, shear load, transverse shear load, air-tight load, floor load, calculating structural strain responses for the various reference loads alone, and generating corresponding reference load strain matrices: axle pressure reference load strain matrix A z Bending reference load strain matrix A w Shear reference load strain matrix A j Transverse shear reference load strain matrix A h Airtight reference load strain matrix A q Floor reference load strain matrix A d The basic expression for each strain matrix is as follows:
wherein: a is that z The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the bent plate under the shaft pressure reference load;
positive X-direction strain for the nth cell in the target region under the shaft pressure reference load; />
Positive Y-direction strain for the nth cell in the target region under the axial compressive reference load; />
Is the shear strain of the nth cell in the target region at the axial compressive reference load; a is that w The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the bending reference load; />
Positive X-direction strain for the nth cell in the target region under the bending reference load;/>
positive Y-direction strain for the nth cell in the target region under the bending reference load; />
Is the shear strain of the nth cell in the target region under the bending reference load. A is that j The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the shearing reference load; />
Positive X-direction strain for the nth cell in the target region under shear reference load; />
Positive Y-direction strain for the nth cell in the target region under shear reference load; />
Is the shear strain of the nth cell in the target region at the shear reference load; a is that h The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the transverse shearing reference load; />
Positive X-direction strain for the nth cell in the target region under the transverse shear reference load; />
Positive Y-direction strain for the nth cell in the target region under the transverse shear reference load; />
Is the shear strain of the nth cell in the target region under the transverse shear reference load; a is that q For curved plates at airtight levelUnder load, the strain matrix is composed of positive strain in the X direction and positive strain in the Y direction of all units in the curved plate and shearing strain; />
Positive X-direction strain for the nth cell within the target area under the hermetic reference load; />
Positive Y-direction strain for the nth cell within the target region at the hermetic reference load; />
Is the shear strain of the nth cell within the target region at the hermetic reference load; a is that d The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the reference load of the floor; />
Positive X-direction strain for the nth cell in the target area under the floor reference load; />
Positive Y-direction strain for the nth cell in the target area under the floor reference load; />
Is the shear strain of the nth cell in the target area under the floor reference load.
(3) Multiplying each reference load strain matrix by different load coefficients, and superposing to form a combined strain matrix A zuhe ；
A zuhe ＝λ z A z +λ w A w +λ j A j +λ h A h +λ q A q +λ d A d
Wherein: lambda (lambda) z Load factor lambda as reference load for axle load w For bending reference loadLoad factor of load lambda j Load factor lambda as shear reference load h Load factor lambda of transverse shear reference load q Load factor lambda as airtight reference load d The initial value of all load coefficients is 1.0, which is the load coefficient of the floor reference load.
(4) Using a target strain matrix A * Subtracting the combined strain matrix A zuhe Forming an error strain matrix A wucha ＝A * -A zuhe ；
(5) Forming an objective function F (λ) for calculating a load factor:
wherein:
for error strain matrix A wucha Any of the following; lambda is the load coefficient vector, lambda= [ lambda ] z λ w λ j λ h λ q λ d ]。
(6) And calculating a load coefficient vector lambda of each reference load by using a multidimensional extremum solving method with the minimum value of the function F as a target, namely solving the following problems:
min F(λ),λ∈R n
wherein: f (λ) is a scalar function, λ is a vector.
After the load factor is obtained, the load factor of each load is multiplied by the reference load to obtain the values of the various loads to be applied in the final test.
Finally, various loads are applied to the finite element model comprising the test fixture, the strain cloud image of the curved plate can be calculated, the strain cloud image is compared with the strain cloud image of the curved plate in the full-machine model, the strain cloud image and the strain cloud image are basically consistent (the comparison effect is shown in fig. 3 and 4), and the calculated boundary load of the curved plate can accurately simulate the loaded state of the curved plate in the full-machine.
Claims (7)
1. The method for calculating the test load of the aircraft fuselage curved plate is characterized by comprising the following steps of:
(1) Selecting a target area curved plate from a finite element model of the whole fuselage, and generating a target strain matrix;
(2) Establishing finite element models of a curved plate and a related test fixture, respectively applying various reference loads, calculating structural strain responses under the various reference loads, and generating corresponding reference load strain matrixes;
(3) Multiplying each reference load strain matrix by different load coefficients, and superposing to form a combined strain matrix;
(4) Subtracting the combined strain matrix from the target strain matrix to form an error strain matrix A wucha ；
(5) An objective function F (lambda) for calculating the load factor is formed,
objective function
Wherein (1)>
For error strain matrix A wucha Any of the following; lambda is the load coefficient vector, lambda= [ lambda ] z λ w λ j λ h λ q λ d ]，λ z Load factor lambda as reference load for axle load w Load factor lambda as bending reference load j Load factor lambda as shear reference load h Load factor lambda as transverse shear reference load q Load factor lambda as airtight reference load d The initial value of all load coefficients is 1.0;
(6) And calculating the load coefficient vector lambda of each reference load by using a multidimensional extremum solving method with the minimum value of the function F (lambda) as a target, namely solving: minF (lambda), lambda epsilon R n 。
2. An aircraft fuselage curve test load cell as defined in claim 1The calculation method is characterized in that the calculation process of the step (1) is as follows: selecting a target area curved plate in a finite element model of the whole fuselage, outputting a strain value of each finite element in the target area curved plate according to the existing whole-fuselage strain calculation result, and generating a target strain matrix A * ：
Wherein: a is that * The strain matrix is composed of positive X-direction strain, positive Y-direction strain and shearing strain of all units in the target area in the whole fuselage calculation state;
positive strain in the X direction for the nth cell within the target region; />
Positive strain in the Y direction for the nth cell within the target region; />
Is the shear strain of the nth cell within the target region.
3. The method of claim 1, wherein the reference load in step (2) comprises an axle load, a bending load, a shear load, a transverse shear load, an airtight load, or a floor load.
4. A method of calculating an aircraft fuselage skin curve test load as defined in claim 3, wherein the axial reference load strain matrix a in step (2) z Bending reference load strain matrix A w Shear reference load strain matrix A j Transverse shear reference load strain matrix A h Airtight reference load strain matrix A q Floor reference load strain matrix A d The basic expression of (2) is as follows:
wherein: a is that z The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the bent plate under the shaft pressure reference load;
positive X-direction strain for the nth cell in the target region under the shaft pressure reference load;
positive Y-direction strain for the nth cell in the target region under the axial compressive reference load; />
Is the shear strain of the nth cell in the target region at the axial compressive reference load; a is that w The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the bending reference load; />
Positive X-direction strain for the nth cell in the target region under the bending reference load; />
Positive Y-direction strain for the nth cell in the target region under the bending reference load;
is the shear strain of the nth cell in the target region under the bending reference load; a is that j The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the shearing reference load; />
Positive X-direction strain for the nth cell in the target region under shear reference load; />
Positive Y-direction strain for the nth cell in the target region under shear reference load; />
Is the shear strain of the nth cell in the target region at the shear reference load; a is that h The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the transverse shearing reference load; />
To shear the reference load in the transverse directionPositive X-direction strain of the nth cell within the under-load target region; />
Positive Y-direction strain for the nth cell in the target region under the transverse shear reference load; />
Is the shear strain of the nth cell in the target region under the transverse shear reference load; a is that q The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the airtight reference load; />
Positive X-direction strain for the nth cell within the target area under the hermetic reference load; />
Positive Y-direction strain for the nth cell within the target region at the hermetic reference load; />
Is the shear strain of the nth cell within the target region at the hermetic reference load; a is that d The strain matrix is formed by positive X-direction strain, positive Y-direction strain and shearing strain of all units in the curved plate under the reference load of the floor; />
Positive X-direction strain for the nth cell in the target area under the floor reference load; />
Positive Y-direction strain for the nth cell in the target area under the floor reference load; />
Is the shear strain of the nth cell in the target area under the floor reference load.
5. The method of calculating the test load of an aircraft fuselage curve as defined in claim 4, wherein the calculation in step (3) is as follows: multiplying each reference load strain matrix by different load coefficients, and superposing to form a combined strain matrix A zuhe ；
A zuhe ＝λ z A z +λ w A w +λ j A j +λ h A h +λ q A q +λ d A d
Wherein: lambda (lambda) z Load factor lambda as reference load for axle load w Load factor lambda as bending reference load j Load factor lambda as shear reference load h Load factor lambda as transverse shear reference load q Load factor lambda as airtight reference load d The initial value of all load coefficients is 1.0, which is the load coefficient of the floor reference load.
6. The method for calculating the test load of the aircraft fuselage curve according to claim 5, wherein the calculation process in the step (4) is as follows: using a target strain matrix A * Subtracting the combined strain matrix A zuhe Forming an error strain matrix A wucha ＝A * -A zuhe 。
7. A method of calculating a pilot load for an aircraft fuselage skin curve as claimed in claim 1, wherein the process of calculating the load coefficient vector λ is implemented using MATLAB-related optimization functions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910384399.0A CN110135044B (en) | 2019-05-09 | 2019-05-09 | Method for calculating test load of aircraft fuselage curved plate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910384399.0A CN110135044B (en) | 2019-05-09 | 2019-05-09 | Method for calculating test load of aircraft fuselage curved plate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110135044A CN110135044A (en) | 2019-08-16 |
| CN110135044B true CN110135044B (en) | 2023-05-26 |
Family
ID=67576785
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910384399.0A Active CN110135044B (en) | 2019-05-09 | 2019-05-09 | Method for calculating test load of aircraft fuselage curved plate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110135044B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113158516B (en) * | 2021-03-31 | 2023-02-28 | 中国飞机强度研究所 | Method and device for constructing finite element model of clamp of cylindrical structural strength test piece |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105095575A (en) * | 2014-08-26 | 2015-11-25 | 国家电网公司 | Stress calculation method for no-linear flexible members without influence of external environmental factors |
| CN105203310A (en) * | 2015-09-17 | 2015-12-30 | 中国飞机强度研究所 | Shaft part load calibration method and system for aircraft engine |
-
2019
- 2019-05-09 CN CN201910384399.0A patent/CN110135044B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105095575A (en) * | 2014-08-26 | 2015-11-25 | 国家电网公司 | Stress calculation method for no-linear flexible members without influence of external environmental factors |
| CN105203310A (en) * | 2015-09-17 | 2015-12-30 | 中国飞机强度研究所 | Shaft part load calibration method and system for aircraft engine |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110135044A (en) | 2019-08-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109918712B (en) | Calculation method for solving composite stress intensity factor based on p-type finite element method and contour integral method | |
| CN106919767A (en) | Automobile body-in-white lightweight analysis method | |
| CN108875138A (en) | Consider the structure optimization of the increasing material manufacturing part of manufacture initiation state | |
| CN110889166B (en) | Lightweight design method for aviation bearing bracket based on thermal coupling constraint | |
| CN110990944B (en) | Vehicle frame multi-target topology optimization method based on weight ratio calculation | |
| CN110135044B (en) | Method for calculating test load of aircraft fuselage curved plate | |
| CN110210130B (en) | Shape optimization method for I-beam two-dimensional model | |
| CN110515301B (en) | Improved ADMM algorithm combined with DMPC | |
| CN104561848A (en) | Creep age forming technological method | |
| Johnsen | Structural topology optimization: basic theory, methods and applications | |
| CN112528411A (en) | Geometric nonlinear structure noise vibration response calculation method based on modal reduction | |
| CN111610091A (en) | Automatic calibration method for discrete element Hertz contact parameter during simulation of geotechnical material | |
| CN109446731A (en) | A kind of Geotechnical Engineering method based on ABAQUS | |
| CN111159943A (en) | Buckling treatment method for movable wing surface sealing structure | |
| WO2023142333A1 (en) | Correction method and system for thin-walled cylindrical shell model | |
| CN111159879B (en) | Nail load processing method of centralized load transmission structure | |
| CN113094946A (en) | Phase field model localization self-adaptive algorithm for simulating material cracking | |
| CN104029826A (en) | Taring computing method for airplane structural strength test | |
| CN109241685B (en) | Protective structure lightweight design method under equivalent static load effect | |
| CN106557599A (en) | A kind of space force system loading spectrum preparation method | |
| Roque et al. | Transient analysis of composite and sandwich plates by radial basis functions | |
| CN114818410A (en) | Simulation method for fatigue strength of butt solid weld | |
| CN113065259B (en) | Coordination method for positions and postures of wallboard assembly and skeleton | |
| Thurnherr et al. | Investigation of failure initiation in curved composite laminates using a higher-order beam model | |
| Shang et al. | Topology optimization for coupled acoustic-structural systems under random excitation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |