Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by and is under the jurisdiction of National Technical Committee on Technical Product Documentation of Standardization Administration of China (SAC/TC 146).
General principles of structural finite element analysis for mechanical products
1 Scope
This standard specifies the types, processes, general requirements, model building rules, finite element analysis ("analysis" for short), result evaluation, result output and report preparation of structural finite element analysis for mechanical products.
It is applicable to the structural finite element analysis for mechanical products.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2298-2010 Mechanical vibration, shock and condition monitoring - Vocabulary
GB 3100-1993 The international system of units and its application
GB 3101-1993 General principles concerning quantities, units and symbols
GB/T 10853-2008 Terminology for the mechanism and machine science
GB/T 26099.1-2010 General principles of three-dimensional modeling for mechanical products - Part 1: General requirements
GB/T 31054-2014 Computer aided engineering for mechanical products - Finite element numerical calculation - Terminology
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2298-2010, GB 3100-1993, GB 3101-1993, GB/T 10853-2008, GB/T 26099.1-2010 and GB/T 31054-2014 as well as the following apply.
3.1
finite element modeling
process of building finite element model, including steps such as building and/or processing of geometric model, definition of material property, meshing and boundary condition application
3.2
material property
set of data describing the physical properties of materials used in the structure of mechanical products
3.3
boundary condition
describing the data information of geometric and physical conditions on the solution domain boundary, such as force, temperature, velocity, displacement and other loads for mechanical products under a given working condition
3.4
stress concentration
phenomenon that the stress value increases obviously due to the sharp change of stiffness in the local transition region of the structure
3.5
node
hinge points between elements
Note: Each element only communicates with neighboring elements and the outside at the node.
[GB/T 31054-2014, definition 3.1.5]
3.6
element
minimum solution domain with geometric and physical properties
[GB/T 31054-2014, definition 3.1.4]
3.7
zero dimensional element
element represented as points, such as mass element
3.8
one dimensional element
element represented as line segments, such as stiff element, bar element and beam element
[GB/T 31054-2014, definition 3.3.6]
3.9
two dimensional element
element represented as planar chips, such as rectangular element and triangular element
[GB/T 31054-2014, definition 3.3.7]
3.10
three dimensional element
element represented as solid body, such as tetrahedron element and hexahedral element
[GB/T 31054-2014, definition 3.3.8]
3.11
mass element
element represented with only mass property
3.12
spring element
element with spring constraint between representational structures
3.13
bar
member whose length is much longer than the dimensions in other directions
[GB/T 31054-2014, definition 4.1.4]
3.14
beam
a kind of bar structures which bears lateral load and is mainly bent in deformation
[GB/T 31054-2014, definition 4.1.3]
3.15
plane/shell
a kind of structures whose dimension in thickness direction is much smaller than that in length and width directions
Note: That with flat surface is called a plane, and that with curved surface is called a shell.
[GB/T 31054-2014, definition 4.1.4]
3.16
solid body
three-dimensional geometry with closed volume formed by faces or edges
[GB/T 26099.1-2010, definition 3.2]
3.17
high order element
element with boundary described with quadratic function or higher order function
3.18
low order element
element with boundary described with linear function
3.19
constraint
various constraints to reduce system freedom
[GB/T 10853-2008, definition 3.3.13]
3.20
displacement
time variable that represents the position change of a point on an representative object relative to a reference system
[GB/T 2298-2010, definition 2.1]
3.21
loads
system of force exerted on an object or system
[GB/T 10853-2008, definition 5.2.58]
3.22
strength
capability of the structure to resist damage
[GB/T 31054-2014, definition 4.1.5]
3.23
stiffness
capability of the structure to resist deformation
[GB/T 31054-2014, definition 4.1.6]
3.24
structural statics analysis
structural response analysis not affected by time parameters under static or approximate static load
[GB/T 31054-2014, definition 3.1.10]
3.25
structural dynamics analysis
analysis of structural dynamics characteristics and response under time-varying loads, inertia and damping effects
[GB/T 31054-2014, definition 3.1.11]
3.26
aspect ratio
quantity describing the ratio of the longest side to the shortest side of a two dimensional or three dimensional element
3.27
slenderness
ratio of the effective length to the gyration radius of a bar
3.28
warpage
degree of deviation of an element from the plane, which is used to check the warpage of the element
3.29
skew
mathematical quantity describing the degree of distortion of an element
3.30
interior angle
value of the included angle of a triangular element or a quadrilateral element, which is often used to describe the mathematical quantity of the maximum interior angle or the minimum interior angle of an element
4 Types
4.1 Structural statics analysis
Statics analysis is adopted when inertia and damping have little or no influence on structural mechanical properties.
4.2 Structural dynamics analysis
It mainly includes modal analysis, harmonic response analysis, spectral analysis and transient dynamics analysis. Dynamics analysis shall be adopted when the influence of inertia and damping on structural mechanical properties is non-negligible.
5 Processes
The processes of structural finite element analysis for mechanical products mainly include five parts: finite element modeling, finite element analysis, evaluation of finite element analysis result, output of finite element result and preparation of analysis report, which are detailed in Annex A.
6 General requirements
6.1 Before the building of the finite element model, the finite element analysis scheme shall be formulated according to the structural characteristics of mechanical products, the characteristics of loads and constraints (or boundary conditions), the simulation purpose, the simulation cycle and the calculation resources.
6.2 When simplifying the geometric model, on the premise of ensuring the accuracy of finite element analysis of the concerned parts, the geometric model details such as edges and corners, small bosses and small grooves of the structure shall be simplified as much as possible.
6.3 When selecting elements, the types of elements shall be reasonably selected according to the geometric model of mechanical products, the characteristics of loads and constraints, and the types and purposes of finite element analysis, so as to ensure the calculation accuracy.
6.4 In case of meshing, the area with slow stress change and the area of no interest (the area built into the model only for force transmission) shall be coarsened and the area with sharp stress change and the area of interest shall be refined.
6.5 The calculation method shall be selected according to the type of structural finite element analysis for mechanical products, the requirements of analysis results, the applicable scope, advantages and disadvantages of the algorithm, the scale of finite element model and computer resources.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Types
5 Processes
6 General requirements
7 Modeling rules
8 Analysis
9 Result evaluation
10 Result output
11 Report preparation
Annex A (Informative) Flow chart of structural finite element analysis for mechanical products
Annex B (Informative) Unit system and element mass inspection index
