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Reprentation o f「esiduaL stress symbol in the technical product documentation 技术产品文件中残余应力符号的表示方法
By Li Peilu, Xu Chunguang, Song Wenyuan, Li Shuangyi, Ma Pengzhi
李培禄徐春广宋文渊栗双怡马朋志
Abstract: A reprentation of residual stress graphic symbols in technical product documents is studied. The residual stress state of the product can be annotated in the technical product documents such as design drawings, process documents, test reports, papers and monographs. The composition of residual stress and the design of basic symbols, measurement method symbols, relief method symbols and state symbols of residual stress, and the reprentation of annotation for residual stress in documents are introduced. Residual stress symbol can be ud in the design, manufacturing, inspection and rvice for the residual stress state requirements of the products in the mechanical manufacturing industry, as well as in Light industry, daily necessities and other related industries.Keywords:
technical product documentation, residual stress, symbol, annotation: stress measurement, stress relief
Introduction
Residual stress is the lf-balanced stress remaining on the surface and inside of the component after the external Load of the product component is removed, and it has the characteristics of the three-dimensional space vector distribution of size, direction and position111.Residual stress is a basic property of product components, which exists in the entire Life cycle of the product, and has an important impact on the strength, fracture resistance, fatigue strength, dim ensional stability of the product components, corrosion resistance, manufacturing quality, and rvice reliability. It has become an important basic parameter describing the performance of product materials and components such as geometric tolerances, surface roughness and material hardness. In the drawing of the product design stage,clear residual stress requirements are given, so that the residual stress state can be effectively identified and controlled during product manufacturing, acceptance and rvice, so as to further improve and ensure product quality and rvice safety.
The purpo of designing the residual stress symbol is to satisfy the effective expression of the tech
nical requirements for the residual stress of the component material during the product Life cycle. In the production and rvice Links of design, manufacturing, inspection, testing, physical and chemical measurement, etc., the symbolic reprentation and annotation of the technical requirements such as the distribution state and value of the residual stress of the component are realized.
It should be noted that when the residual stress symbol is ud in product design, the manufacturing cost and its necessity should be considered.
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Design of symbols
Composition of symbol
The residual stress symbol consists of basic symbols and supplementary requirements, as shown in Figure 1. The basic symbol is compod of an inverted equilateral triangle, the corners of the equilateral triangle point perpendicular to the surface of the relevant product component. For the convenience of annotation, a guide line can be drawn on the upper left or upper right of the basic symbol to point to the relevant surface of the product component.
Supplementary requirements include the residual stress state sym bol R S S(Residual Stress State), parameter sym bol o and G(h),measuring method symbol R S M(Residual Stress Measurement), relieving method symbol R SR(Residual Stress Relief), additional explanation Info, etc., where, R S S describes the direction, states of tension and compression and distribution state of residual stress.
The sym bols can be annotated with one or more according to needs, or they can be annotated in combination according to needs, and relevant information instructions can also be added.
r sm\^s^/rsr|
F ig u re1: C o m p o s it i o n o f r e s id u a l s t r e s s s y m b o l
In Figure 1, a reprents the value of residual stress at a point on the surface of the component. G(h)reprents the gradient of residual stress, namely the rate of change of residual stress descending or ascending. For the sizes of symbols, h is the height of numbers and letters, d'is the line width of symbols, d is the Line width of letters and numbers, Hj and H2 are heights, H2 depending on the number of label lines. The recommended sizes are shown in Table 1.
T a b le1: R e c o m m e n d e d s iz e s o f r e s id u a l s t r e s s s y m b o ls
h d’d h2
2.50.250.25
3.57.5
3.50.350.35 5.010.5
S iz e s
(m m)
5.00.500.507.015
7.00.700.701021
10 1.00 1.001430
14 1.40 1.402042
20 2.00 2.002860
In engineering, the m agnitude and gradient distribution of normal stress and shear stress have an important impact on product quality and performance. There should be clear requirements and clear signs in the stages of structural design, manufacturing process, combined asmbly, inspection and testing, and safe rvice. G(/i) reprents the gradient of residual stress, that is, changes to the inside of the component material bad on the value o of the residual stress on the surface of the component. G{h) is a polynomial function, expresd as
G(h)=o^ah±^h2±—±yhn
where, h is the depth, the unit is |jm. a,and y are polynomial coefficients, n is an integer greater than or equal to 3. For example, if G(/7=0)=c j,it means that the residual stress layer of the component is infinitely thin, that is, the surface residual stress is a.If G(h)=890-680/], it means that the residual stress decreas Linearly from the surface to the inside with the surface residual stress of 890 MPa. If G(h=5)=0t it means the longitudinal residual stress depth of the residual stress, that is, the residual stress o remains unchanged within the depth range of h=S pm.
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Measurement method symbols
According to different principles, residual stress measurement (testing) methods include three types: destructive testing, micro-destructive testing and nondestructive testing.
The destructive and micro-destructive testing methods of residual stress are mechanical destructive testing methods, also known as a mechanical method. Its basic principle is to u drilling, excision and other destructive methods to LocaUy cut or parate the area where the residual stress is concentrated, the internal residual stress will be partially relead. By measuring the elastic deformation of the component after the stress is relead, the Local residual stress is obtained according to the elastic modulus of the material and the elastic constitutive equation (such as Hooke's Law), and then the entire component is estimated the distribution of residual stress.The destructive testing methods for residual stress mainly include contour method, slitting method, peeling method, splitting method, grooving method and cutting method. The micro-destructive testing methods mainly include the drilling method, the deep hole method and the ring core method. The two mechanical methods need to relea the stress when measuring the residual stress, after the partial cutting and paration, it will cau irreversible damage to the component. However, the mechanical method has a more complete theory and mature technology, and has been widely ud i
n field tests.The non-destructive testing method of residual stress is a physical m easuring method and w ill graduaUy replace the conventional destructive testing methods due to its non-destructive characteristics. The measurement principle is to u the acoustic elasticity, magnetism, crystal diffraction phenomenon, photoeLasticity or thermoelasticity and other physical characteristics in material to determine residual stress. Non-destructive testing methods for residual stress
mainly include Indentation Strain method, Ultrasonic method, X-ray Diffraction method, Synchrotron X-ray D iffractio n m ethod, Neutron Diffraction method, M agnetic method, Raman Spectroscopy method, PhotoeLasticity method, Curvature method, Thermoelastic method and Scanning Electron Acoustic Microscope method, etc.
In Figure 1, the symbol of the measurement method of residual stress can be further specifically expresd as R SM -X X /Y Y , X X is the abbreviation of the residual stress measurement method, Y Y is refined into the specific method, and only X X or X X /Y Y is annotated. Here is a List of veral residual stress measurement methods commonly ud in engineering at prent, as shown in Table 2.
T a b le 2: M e a s u r e m e n t m e t h o d s y m b o ls o f r e s id u a l s t r e s s
Symbol
Description
R S M -C o n t o u r C o n t o u r m e t h o d R S M -S lit t in g S lit t in g m e t h o d
R S M -L R L a y e r -R e m o v a l m e t h o d , LR
R S M -H D S G H o le -D r illin g S t r a in -G a g e m e t h o d , H D S C [2]R S M -D H D D e e p -H o le D rillin g m e t h o d , D H D R S M -R C R in g -C o r e m e t h o d , RC
R S M -S R S G S e c t io n in g R e la x a t io n S t r a in -G a g e m e th o d , S R S G l3]
R S M -IS G In d e n t a t io n S t r a in -G a g e m e th o d , ISG
R S M -U T /L C R U lt r a s o n ic C rit ic a l R e fra c te d L o n g it u d in a l W a v e m e t h o d , U T/LC R 141
R S M -U T /B W U lt r a s o n ic B u lk W a v e m e th o d , U T /B W [5]R S M -R T /X R D X -r a y D iff ra c t io n m e t h o d , R T /X R D [6]
R S M -R T /S X R D S y n c h r o t r o n X -r a y D iffra c tio n m e t h o d , R T /S X R D tn R S M -R T /N D N e u t r o n D iff ra c t io n m e t h o d , RT/N D 181R S M -M T M a g n e t ic m e t h o d , M T [9]
R S M -R S
R a m a n S p e c t r o s c o p y m e th o d , R S R S M -C u r v a t u re C u r v a t u r e m e t h o d
R S M -P E
P h o t o -e la s t ic m e t h o d , PE
Relief method symbols
In engineering, according to the different types of forces acting on the components, the residual stress control methods include thermal method and mechanical method. The thermal method is to adjust the internal structure of the component by changing
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the temperature to relax the residual stress. The mechanical method is to apply static or dynamic stress to the component through mechanical, electromagnetic and other m ethods to reduce or redistribute the residual stress. The thermal methods include Natural Stress Relief method and Heat Treatment method (Annealing). Mechanical methods include Vibratory Stress Relief method, High Energy Acoustic Beam method, High Energy Shot Peening method, Ul-trasonic Peening/lm pact Treatment, Hammering method, Lar Shock Peening/Processing method, Ultrasonic Cavitation Peening method, etc.
Sim ilar to the sym b ol of the residual stress measurement method, the symbol of relief method can be further specifically expresd as RSR-XX, and X X is the abbreviation of the residual stress relief method.
Table 3: Relief method symbols of residual stress Symbol Description
R S R-N S R N a t u r a l S t r e s s R e lie f m e t h o d, N S R
R S R-H T H e a t T re a tm e n t, H T 1101
R S R-H A B H ig h E n e r g y A c o u s t i c B e a m m e t h o d, H N A B【”】
R S R-E T E x p lo s io n T re a tm e n t, ET 1121
R S R-H E S P H ig h E n e r g y S h o t P e e n in g m e t h o d, H E S P(13]
R S R-U P T/U IT U lt r a s o n ic P e e n in g/ Im p a c t T re a tm e n t, U PT/U IT
R S R-V S R V ib r a t o r y S t r e s s R e lie f m e t h o d, V S R1141
R S R-U V S R U lt r a s o n ic V ib ra t o r y S t r e s s R e lie f m e t h o d, U V S R
R S R-O L O v e r-L o a d in g m e t h o d, O L
R S R-H M H a m m e r in g m e t h o d, H M
R S R-L S P L a s e r S h o c k P e e n in g/P r o c e s s in g m e t h o d, L S P
R S R-U C P U lt r a s o n ic C a v it a t io n P e e n in g m e t h o d, U C P1151
R S R-P E C T P u ls e d E le c tric C u r r e n t T re a tm e n t, PEC T
R S R-P M T P u ls e d M a g n e t ic T re a tm e n t, P M T
State symbols
The state symbol is the most important part of the residual stress symbol. It can clearly indicate the direction, tension and compression state and distribution state of the residual stress. According to the specific
SimilarLy, only X X is annotated. Several residual stress distribution of the residual stress and the requirements relief methods com m only ud in engineering at of the product u function, it can be combined into a prent are in Table 3. variety of residual stress states in Table 4.
T a b le 4: S t a t e s y m b o l s o f r e s id u a l s t r e s s
Sym bol D escription
n Zero residual stress
<>Tangential (horizontal) ID tensile residual stress
Normal (vertical) 1D tensile residual stress
Tangential (horizontal) ID compressive residual stress
^Normal (vertical) 1D com pressive residual stress
\ID tensile residual stress in any direction
^ID com pressive residual stress in any direction
+2D tensile residual stress in the horizontal and vertical directions
屮2D com pressive residual stress in the horizontal and vertical directions
2D tensile and com pressive residual stress in the horizontal and vertical directions, respectively
+2D com pressive and tensile residual stress in the horizontal and vertical directions, respectively
X2D tensile residual stress in any direction
X2D com pressive residual stress in any direction
X2D tensile and compressive residual stress in any direction (except the vertical and horizontal directions)
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T a b le 5: E x a m p le s o f r e s id u a l s t r e s s s y m b o ls d e s c r ip t io n
Symbol Description
Zero residual stress state, PE refers to Photo-elastic method, HT/AN refers to Heat Treatment
(Annealing).
280
280G(〇)
Tangential (horizontal) ID tensile residual stress. The surface residual stress is 280 MPa, and it is distributed according to the gradient function G(A)(MPa) from the surface to the inside of the component. MT refers to Magnetic method, HAB refers to High Energy Acoustic Beam method.
2D tensile residual stress in the horizontal and vertical directions. From the surface o f the component to the internal depth o f h, uniformly distribute the tensile residual stress of 420 MPa. RC refers to Ring-Core method, NSR refers to Natural Stress R elief method.
2D tensile and compressive residual stress in the horizontal and vertical directions, respectively. The residual stress is 280MPa, only distributed on the surface o f the component. RT/XRD refers to X-ray Diffraction method, HM refers to Hammering method.
2D tensile and compressive residual stress in any direction (except the vertical and hori
zontal directions). RT/N refers to Neutron Diffraction method, PMT refers to Puld Magnetic Treatment.
Description examples
Through the combined expression of the basic symbols and supplementary requirements, the value
and gradient, direction, tension and compression states of the residual stress of the product components can be clearly en, as well as the measurement method ud when measuring the component stress and the relief method ud when the component is subjected to stress relief. Several description examples of residual stress symbols are in Table 5.
Annotations
Sim ilar to such as surface roughness sym bols and geometric tolerances symbols, unless otherwi specified, the residual stress technical indicators annotated on the draw ing are for the technical requirements after a certain process is completed. When annotating, the sign and reading direction of residual stress are consistent with the annotation and reading direction of the size.
v ▽
(C) (d)
F ig u r e 2: A n n o t a t e d o n t h e s u r f a c e o f t h e c o m p o n e n t
(a) (b )
F ig u re 3: A n n o t a t e d o n t h e c o n t o u r lin e (a) o r e x t e n s io n lin e (b)
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