Abaqus - Basic

Principle

Unit

Abaqus doesn’t have a fixed unit system. So we need to choose a matching set of units for each quantity.

量纲 Dimension	单位Units Kg-m-s	单位Units Kg-mm-s	单位Units T-mm-s-Mpa	单位Units g-mm-s
长度L	$ m $	mm $ \rm = 10^{-3} m $	mm $ \rm = 10^{-3} m $	mm $ \rm = 10^{-3} m $
质量M	$ Kg $	$ Kg $	$ T $ (吨) $ \rm 10^3Kg $	g $ \rm 10^{-3}Kg $
时间t	s	s	s	s
温度T	K	K	K	K
面积 $ A \sim L^2 $	$ \rm m^2 $	$ \rm mm^2 $ $ = \rm 10^{-6} m^2 $	$ \rm mm^2 $ $ = \rm 10^{-6} m^2 $	$ \rm mm^2 $ $ = \rm 10^{-6} m^2 $
体积 $ V\sim L^3 $	$ \rm m^3 $	$ \rm mm^3 $ $ = \rm 10^{-9} m^3 $	$ \rm mm^3 $ $ = \rm 10^{-9} m^3 $	$ \rm mm^3 $ $ = \rm 10^{-9} m^3 $
力F	N(牛顿、牛) $ =\rm \frac{Kg \cdot m}{s^2} $	$ \rm \frac{Kg \cdot mm}{s^2} $ $ =\rm 10^{-3}N $	$ \rm \frac{T \cdot mm}{s^2} $ $ =\rm N $	$ \rm \frac{g \cdot mm}{s^2} $ $ =\rm 10^{-6} N $
密度ρ	$ \rm \frac{Kg}{m^3} = \frac{10^{-3}g}{cm^3} $	$ \rm \frac{Kg}{mm^3} = \frac{10^{6}g}{cm^3} $	$ \rm \frac{T}{mm^3} = \frac{10^{9}g}{cm^3} $	$ \rm \frac{g}{mm^3} = \frac{10^{3}g}{cm^3} $
能量、焓、热量 $ \frac{M \cdot L^2}{t^2} $	J(焦耳) $ =\rm N \cdot m = \frac{Kg \cdot m^2}{s^2} $	$ \rm \frac{Kg \cdot mm^2}{s^2} $ $ \rm = 10^{-6}J $	$ \rm \frac{T \cdot mm^2}{s^2} $ $ \rm = 10^{-3}J $	$ \rm \frac{g \cdot mm^2}{s^2} $ $ \rm = 10^{-9}J $
功率、热流量 $ \frac{M \cdot L^2}{t^3} $	W(瓦) $ =\rm\frac{J}{s} = \frac{Kg \cdot m^2}{s^3} $	$ \rm \frac{Kg \cdot mm^2}{s^3} $ $ \rm = 10^{-6}W $	$ \rm \frac{T \cdot mm^2}{s^3} $ $ \rm = 10^{-3}W $	$ \rm \frac{g \cdot mm^2}{s^3} $ $ \rm = 10^{-9}W $
压力、应力、模量 $ \frac{M}{t^2 \cdot L} $	$ \rm Pa = \frac{N}{m^2} = \frac{Kg }{s^2\cdot m} $	$ \rm \frac{Kg }{s^2\cdot mm} $ $ \rm 10^3Pa = kPa $	$ \rm \frac{T }{s^2\cdot mm} $ $ \rm 10^6Pa = MPa $	$ \rm \frac{g }{s^2\cdot mm} $ $ \rm Pa $

Processing

Mesh

For Guided wave (Lamb wave): The largest mesh element size was smaller than 1/10 of the shortest incident wavelength.

Operation skills

Visualization

Question: The result obtained by submitting a job in Abaqus often has mesh grid. Basically, these grid lines are unnecessary sometimes. So how to remove the mesh grid lines?

Method/Steps:

- open the result file in "Visualization".
- Select the "Options" tab and click on the "Common" option.
- "Common Plot Options" --> "Basic" --> "Visible Edges" --> Select "Free edges" or "No edges".

Materials

$ T-mm-s-Mpa $

steel

Properties	Value	Abaqus
Denisity	$ 7.85 g/cm^3 = 7850 kg/m^3 = 7.85 \times 10^{-9} T/mm^3 $	$ 7.85 \times 10^{-9} $
Young’s modulus	$ 210 GPa = 210 000 MPa $	$ 210 000 $
Poisson Ratio	0.3	0.3

aluminum

Properties	Value	Abaqus
Denisity	$ 2.7 g/cm^3 = 2700 kg/m^3 = 2.7 \times 10^{-9} T/mm^3 $	$ 2.7 \times 10^{-9} $
Young’s modulus	$ 70 GPa = 70 000 MPa $	$ 70 000 $
Poisson Ratio	0.33	0.33

Adhesive [Araldite 2011]

Ref:

[1] Polar Coordinate for Damage Imaging of Adhesively Bonded Plates Using Ultrasonic Guided Waves and Laser Doppler Vibrometer Measurements

Properties	Value	Abaqus
Denisity	$ 1.05 g/cm^3 = 1050 kg/m^3 = 1.05 \times 10^{-9} T/mm^3 $	$ 1.05 \times 10^{-9} $
Young’s modulus	$ 1.65 GPa = 1650 MPa $	$ 1650 $
Poisson Ratio	0.4	0.4

T300

unidirectional laminate [单向层压板]

Ref:

[1] Design of fiber-reinforced composite pressure vessels under various loading conditions

[2] Micromechanics Models for Viscoelastic Plain-Weave Composite Tape Springs

Properties	Value
Elastic modulus in fiber direction (GPa)	181
Elastic modulus in matrix direction (GPa)	10.3
In plane shear modulus (GPa)	7.17
Major Poisson’s ratio	0.28

(Self-defined)

Properties	Value	Abaqus
Mass density	1600 $ kg/m^3 $	1.6e-9
$ E_1 $	181 $GPa$	181000
$ E_2 $	10.3 $GPa$	10300
$ E_3 $	10.3 $GPa$	10300
$ G_12 $	7.17 $GPa$	7170
$ G_13 $	7.17 $GPa$	7170
$ G_23 $	3.4 $GPa$	3400
$ \nu_12 $	0.28	0.28
$ \nu_13 $	0.28	0.28
$ \nu_23 $	0.4	0.4

Dispersion curves @ Dispersion Calculator

Export

注意导出out-of-plane的振动数据时，其方向不一定是z轴，特别是从外部文件导入的数据。