CN109991401A - A kind of consideration is gathered materials the three-dimensional random number test specimen generation method of feature - Google Patents
A kind of consideration is gathered materials the three-dimensional random number test specimen generation method of feature Download PDFInfo
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Abstract
Gather materials the three-dimensional random number test specimen generation method of feature the present invention relates to a kind of consideration, comprising the following steps: (1) by Digital Image Processing or the method for manual measurement, acquisition is gathered materials feature and statistical parameter;(2) basic model that individually gathers materials mutually being inscribed with specified partial size sphere is established;(3) by writing function setup random planar, plane cutting is carried out to basic model, to obtain the more complicated space structure that gathers materials;(4) gradation particle is launched using the uniform algorithm of Gen, and is replaced using irregularly gathering materials;(5) it will irregularly be gathered materials by step (4) and successively launched, and carrying out repeatedly circulation makes coarse aggregate accumulation body reach specified altitude assignment;(6) it generates and contacts with each other but nonoverlapping regularly arranged particle, reconstruct three-dimensional random number test specimen.Three-dimensional random number test specimen generation method of the invention, can it is convenient, effectively realize the three-dimensional dispensing irregularly gathered materials, and construct the microscopical structure for meeting true asphalt.
Description
Technical field
Gather materials the three-dimensional of feature the present invention relates to asphalt Three Dimensional Discrete Element emulation technology more particularly to a kind of consideration
Random digit test specimen generation method.
Background technique
Asphalt is not the homogeneous material that traditional mechanics are assumed, as a kind of heterogeneous material, mechanical property is answered
It is codetermined by the property and feature of each component (gather materials, asphalt mortar, bituminous mortar and gap etc.).Wherein, gather materials with complicated geometric form
Shape, technological achievement also focuses mostly in this at present, but its generating algorithm is rarely introduced into the relevance parameter for feature of really gathering materials, from
And leads to model construction and actual conditions there are still certain gaps.Meanwhile the network model that gathers materials established in every possible way needs to count
The numerous small units of mesh, memory needed for will certainly greatly increasing operation, this method is undesirable under the conditions of active computer,
Therefore it also needs that gather materials characteristic parameter and mixture model suitably simplify.
Summary of the invention
It is an object of the invention to overcome deficiency present in above-mentioned technology, a kind of true feature of gathering materials (throwing of consideration is provided
Shadow face polygon and length axial ratio) asphalt number test specimen generation method, can quickly and efficiently simulate pitch mixing
Expect three phase space structures and mechanical property.
To achieve the above object, The technical solution adopted by the invention is as follows:
Consider the three-dimensional random number test specimen generation method of feature of gathering materials, comprising the following steps:
(1) by Digital Image Processing or the method for manual measurement, gather materials feature and statistical parameter are obtained;
(2) basic model that individually gathers materials mutually being inscribed with specified partial size sphere is established;
(3) by writing function setup random planar, plane cutting is carried out to basic model, to obtain more complicated collection
Material space structure;
(4) gradation particle is launched using the uniform algorithm of Gen, and is replaced using irregularly gathering materials;
(5) it will irregularly be gathered materials by step (4) and successively launched, and carrying out repeatedly circulation makes coarse aggregate accumulation body reach finger
Fixed height;
(6) it generates and contacts with each other but nonoverlapping regularly arranged particle, reconstruct three-dimensional random number test specimen.
Further, feature of gathering materials described in step (1) is characterized the major and minor axis of the polygon number of edges sum aggregate material on perspective plane
Rate, the statistical parameter are to carry out the characteristic parameter that normal curve returns to statistical result.
Further, the basic model that individually gathers materials described in step (2) is the pros using square as the cuboid of bottom surface
Shape side length can be by gather materials maximum particle diameter and fills unit radius relationship using being uniformly distributed random determination, and the Gao Zecai of model
It is determined with the normal distyribution function of high axis ratio.
Further, cutting described in step (3) includes primary cutting to obtain pentagon perspective plane, or including repeatedly weight
To obtain hexagon, heptagon or the octagonal projection plane that gathers materials, when cutting, controls the value model of each random number θ for multiple cutting
Difference at least 0.1 is enclosed, to guarantee the validity cut every time.
Further, it is replaced with described in step (4) after the coordinate for exporting each sphere by programming with by step (2)
Irregularly gather materials with what step (3) obtained and substitute generated sphere, wherein collection discharge position is by ball of receiving in its basic unit
The heart determines, rotatable certain angle.
Further, gather materials described in step (5) accumulation body default drop spaces should be default height of specimen 2.0~
3.0 times, control upper wall body compresses test specimen, until reaching default height of specimen, and by contact less than 0.01kN's
Mean exposure power judges test piece balance.
Further, reconstructing method described in step (6) is whether judge to generate particulate units and original aggregate particle set
Overlapping is defined as collection material unit if overlapping, otherwise is mortar unit, and the last a certain number of particles of random erasure are pre- to realize
If voidage.
Compared with prior art, the beneficial effects of the present invention are:
The present invention utilizes simple matrix and cutting algorithm using gather materials feature and normal state statistical result as basis of reality
Can it is very convenient, effectively realize the three-dimensional dispensing irregularly gathered materials, and the three-dimensional component principle of bound bitumen mixture, can
To construct the microscopical structure for meeting true asphalt.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
It obtains other drawings based on these drawings.
Fig. 1 is the basic model that gathers materials in embodiment;
Fig. 2 is model plane cutting schematic diagram in embodiment;
Fig. 3 is that aggregate grading replaces flow chart in embodiment;
Fig. 4 is the accumulation balance schematic diagram that gathers materials in embodiment;
Fig. 5 is final asphalt three-dimensional random number test specimen discrete element analysis schematic diagram in embodiment.
Specific embodiment
Below with reference to embodiment and attached drawing, the present invention is described further, and embodiments of the present invention include but unlimited
In the following example.
Embodiment 1
By taking the digital test specimen of asphalt AC-20 generates as an example and it is described with reference to the accompanying drawings implementation step of the invention
Suddenly.The gradation of asphalt AC-20 is shown in Table 1.
1 asphalt AC-20 gradation table of table
Sieve pore (mm) | 19 | 16 | 13.2 | 9.5 | 4.75 | <4.75 |
Meter is divided to tail over percent of pass (%) | 2.4 | 10.6 | 16.6 | 13.7 | 20.2 | 36.5 |
Specific asphalt number test specimen modeling process is as follows:
(1) gather materials feature and statistical parameter are obtained
It is needed although can not be studied with regard to all individuals investigated with regard to sample for the representativeness for guaranteeing investigation sample
It is totally randomly selected, it is contemplated that number of gathering materials needed for a bitumen mixture specimen, setting nominal maximum aggregate size are
The extraction 100 of gathering materials of the section 19mm shelves, each shelves of other partial sizes not less than 4.75mm gather materials sampling respectively 200.
Determine that different-grain diameter gathers materials the regularity of distribution of perspective plane polygon number of edges using image method, and by manually using trip
Mark calliper to measure obtains gathering materials greatest cross-section height and the largest axis length gathered materials, both obtains the relation of ratio
Cloth.Normal distribution curve fitting is carried out to the two statistical data using formula (1), obtains corresponding normal state statistical parameter.
(2) individually gather materials basic model
The space structure to gather materials is regarded as in the ball interior of certain radius using square as the cuboid of bottom surface, it is square
Shape side length can be shown in formula (2) by gather materials maximum particle diameter and fills unit radius relationship using random determination is uniformly distributed, rectangle
It is high then determined using the normal distyribution function of high axis ratio, see formula (3), mould is generated according to regularly arranged overlapping using fills unit
The spacing of type, the centre of sphere is 1 times of radius, and basic unit of gathering materials is as shown in Figure 1.
In formula, int () is integer function;The uniformly distributed random variable that urand () is 0 to 1;RmaxFor the maximum grain that gathers materials
Diameter;rfillFor fills unit radius.
In formula, y0For initial value;A is amplification coefficient;grand(xc,w2) it is the normal state point for corresponding to true aggregate size range
Cloth stochastic variable, value range is between 1.0 to 3.5, wherein xcFor mean value, w2For variance.
Gather materials in specified grading section at random to guarantee to generate, according to particle size range [Rmax,Rmin], also need addition one to sentence
Off line system is shown in formula (4), repeats the above steps if being unsatisfactory for condition, regenerate random parameter.
Rmin 2< lBottom 2+h2< Rmax 2 (4)
(3) plane cutting is carried out
As shown in Fig. 2, being model cutting schematic diagram, by using body-centered O as the centre of sphere, with the inscribe spherical surface of a height of diameter of model
Upper any point and body-centered determine cutting planes to this exterior normal direction, to guarantee that cut surface can intersect with bottom surface, spherical surface
On random point need to be located on body-centered and height is no more than a certain limitation, it is random that spherical surface can be obtained by figure approximate solution
The variation range of point, specific derivation process are as follows.
Assuming that P (x1,y1,z1) be model inscribed sphere on arbitrary point, point O (x0,y0,z0) be model cuboid body-centered,
Then vector OP is (x1-x0,y1-y0,z1-z0), it may be determined that SECTION EQUATION is shown in formula (5).
(x1-x0)(x-x1)+(y1-y0)(y-y1)+(z1-z0)(z-z1)=0 (5)
The geometrical characteristic of binding model and the restriction range of random point can be obtained the random generation formula of each coordinate of P point, see
Formula (6), formula (7) and formula (8).
y1=y0+0.5hsin(2πθ) (7)
x1=x0+0.5hcos(2πθ) (8)
In formula, θ is to obey the equally distributed random number of 0-1.
Carrying out primary cutting can be obtained pentagon perspective plane, can obtain if repeating cutting step with hexagon, seven sides
Shape and the octagonal projection plane that gathers materials, are controlled by the value range to each random number θ, test indicate that need respectively with
Machine number differs at least 0.1, to guarantee the validity cut every time.
(4) gradation is launched and is replaced
Establish the three-dimensional asphalt cylinder test specimen of 100mm × 100mm.Mineral aggregate by partial size greater than 4.75mm defines
For coarse aggregate, rest part is then reduced to asphalt mortar, bituminous mortar and gap.Then, by the bitumen aggregate ratio of asphalt, voidage with
And the parameters such as mineral aggregate gradation calculate the volume of each shelves coarse aggregate, specific process of launching is shown in Fig. 3, to guarantee that drop spaces are sufficiently large
And it is unlikely to particle spilling, initial sample dimensions can be preset as to high 250mm by debugging, the cylindrical body that diameter is 100mm is empty
Between.
In i-th grade of launch process that gathers materials, first passes through Gen and generate n at random using nominal maximum aggregate size as the sphere of diameter
(gross mass is the setting quality that this grade gathers materials), then exports the coordinate of each ball, is replaced by programming to be gathered materials with random digit
For generated sphere, and the gross mass for generating and gathering materials is calculated, judges whether to reach setting quality, if not reaching yet after the completion of replacement
It arrives, then repeatedly aforesaid operations continue to generate and sphere and gather materials, which, which gathers materials, successively launches and generate according to step after the completion of dispensing
Gather materials at random.
(5) coarse aggregate accumulation and balance
By step 4 carry out coarse aggregate dispensing, then control upper wall body, with constant speed (0.01m/s) to test specimen into
Row compression can add the vibration (5kHz, amplitude are not more than 0.1mm) of certain frequency to guarantee compacting sufficiently on wall,
Until height is reduced to 100 ± 0.1mm, repeatedly circulation makes coarse aggregate particle tend to balance, as shown in Figure 4.
(6) three-dimensional random number test specimen is reconstructed.
On the basis of coarse aggregate skeleton, in test specimen space from top to bottom the arrangement of layer-by-layer create-rule (contact with each other but
Be not overlapped) single particle size particulate units, according to computer operational efficiency, setting particle diameter is 2.5mm, totally 49520
Particle.It writes Fish function and judges whether generation particulate units and former aggregate particle set are be overlapped, are defined as gathering materials if overlapping
Unit, on the contrary it is mortar unit, and all particulate units in single aggregate particle range of convergence are respectively defined as one
Clump block.
By changing grain color and Range order, regularly arranged particulate units are assigned respectively and are gathered materials and mortar phase
Corresponding physical attribute, and delete former aggregate particle set.Simultaneously for asphalt dummy model, it is still necessary to consider gap
The effect of component, a certain number of particles of random erasure are in rule particle unit to realize preset voidage requirement.Such as Fig. 5
It is shown, for obtained final three-dimensional random asphalt number test specimen discrete element analysis.
The above is only a preferred embodiment of the present invention, it should be pointed out that: for the ordinary skill people of the art
For member, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications are also answered
It is considered as protection scope of the present invention.
Claims (7)
- The three-dimensional random number test specimen generation method of feature 1. a kind of consideration is gathered materials, it is characterised in that: the following steps are included:(1) by Digital Image Processing or the method for manual measurement, gather materials feature and statistical parameter are obtained;(2) basic model that individually gathers materials mutually being inscribed with specified partial size sphere is established;(3) by writing function setup random planar, plane cutting is carried out to basic model, to obtain the more complicated sky that gathers materials Between structure;(4) gradation particle is launched using the uniform algorithm of Gen, and is replaced using irregularly gathering materials;(5) it will irregularly be gathered materials by step (4) and successively launched, and carrying out repeatedly circulation makes coarse aggregate accumulation body reach specified height Degree;(6) it generates and contacts with each other but nonoverlapping regularly arranged particle, reconstruct three-dimensional random number test specimen.
- The three-dimensional random number test specimen generation method of feature 2. consideration as described in claim 1 is gathered materials, it is characterised in that: step (1) feature of gathering materials described in is characterized the length axial ratio of the polygon number of edges sum aggregate material on perspective plane, and the statistical parameter is to system Meter result carries out the characteristic parameter that normal curve returns.
- The three-dimensional random number test specimen generation method of feature 3. consideration as described in claim 1 is gathered materials, it is characterised in that: step (2) basic model that individually gathers materials described in is using square as the cuboid of bottom surface, and square side length can pass through maximum of gathering materials Partial size and fills unit radius relationship, which utilize, is uniformly distributed random determination, and the high normal distribution letter for then using high axis ratio of model Number is to determine.
- The three-dimensional random number test specimen generation method of feature 4. consideration as described in claim 1 is gathered materials, it is characterised in that: step (3) cutting described in includes primary cutting to obtain pentagon perspective plane, or including cutting is repeated several times to obtain hexagon, seven Side shape or the octagonal projection plane that gathers materials, when cutting, controls the value range difference at least 0.1 of each random number θ, to guarantee The validity cut every time.
- The three-dimensional random number test specimen generation method of feature 5. consideration as described in claim 1 is gathered materials, it is characterised in that: step (4) it is replaced with described in irregular with being obtained by step (2) and step (3) by programming after the coordinate for exporting each sphere Gather materials and substitutes generated sphere, wherein collection discharge position is determined by receiving the centre of sphere in its basic unit, rotatable certain angle Degree.
- The three-dimensional random number test specimen generation method of feature 6. consideration as described in claim 1 is gathered materials, it is characterised in that: step (5) the default drop spaces of accumulation body of gathering materials described in should be 2.0~3.0 times of default height of specimen, control upper wall body pair Test specimen is compressed, until reaching default height of specimen, and judges test specimen by contacting the mean exposure power less than 0.01kN Balance.
- The three-dimensional random number test specimen generation method of feature 7. consideration as described in claim 1 is gathered materials, it is characterised in that: step (6) reconstructing method described in is to judge whether generation particulate units and former aggregate particle set are be overlapped, are defined as collecting if overlapping Material unit, on the contrary it is mortar unit, and the last a certain number of particles of random erasure are to realize preset voidage.
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CN113553751A (en) * | 2021-07-23 | 2021-10-26 | 长江水利委员会长江科学院 | Coarse particle material three-dimensional block system generation method and device, storage medium and equipment |
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