CN105160052B - Maximized displacement vector fill method is filled based on energetic material approximation ball-type - Google Patents

Abstract

The present invention claims to protect a displacement vector filling method based on the approximate spherical filling of energetic materials, which includes the steps of randomly placing spherical particles into the compression chamber according to the radius from large to small, and after completing the spherical particle placement stage , enter the adjustment stage; the adjustment stage is divided into three processes, that is, the spherical particles move to the negative direction of the x-axis according to the x-axis coordinates from small to large, and then move to the negative direction of the y-axis according to the y-axis coordinates from small to large, and finally press The z-axis coordinates move from small to large in the negative direction of the z-axis; in the present invention, after the above-mentioned particle movement, the inter-particle gaps are minimized, and the cabin can continue to be filled to increase the filling rate.

Description

Displacement Vector Filling Method Based on Maximization of Approximate Spherical Filling of Energetic Materials

technical field

The invention belongs to the fields of material science and computer science, and in particular relates to a method for solving the problem of low filling rate of compression chambers caused by dispersion of spherical particles of different sizes and random positions when filling in the field of energetic material compression, and excessive gaps ,

Background technique

Energetic materials are energetic compounds, referred to as energy materials, meaning high energy density substances (HEDM); it is characterized by the fact that such substances are mostly explosive, deflagration, or other substances that release a large amount of energy at a high rate and high output after specific excitation conditions substance. The mechanical properties of energetic materials mainly refer to the mechanical characteristics exhibited when they are subjected to various external loads (tension, compression, bending, torsion, impact, alternating stress, etc.) under different environments (temperature, medium, humidity). . The properties of energetic materials are affected by various factors such as the internal composition of the material, such as material shape, volume ratio, etc. The change of material formula has a great impact on the overall mechanical properties; at the same time, the material has explosive properties, so the preparation experiment of energetic materials is carried out Research is costly and risky.

In recent years, the numerical simulation of the mechanical properties of energetic materials has received more and more attention. Due to the complexity of the material particle forming process, it is very difficult to clarify its forming mechanism, especially how to simulate the material particle distribution, which has great influence on the experimental process and results. Data is especially important. This simulation adopts Uintah and VisIt software, a large-scale parallel visual numerical simulation tool developed by UCF (Uintah Computational Framework) developed by C-SAFE (Center for the Simulation of Accidental Fires and Explosions) Research Center of the University of Utah.

From the research situation, how to establish the microstructure model of spherical particles is one of the key issues in the process of material particle compression. Foreign scholars Baer ^[1] used the molecular dynamics modeling method to establish a three-dimensional explosive particle mesostructure model with the same size and randomly distributed positions. Domestic Liu Qun ^[2] approximated the explosive particle into a two-dimensional circle, and Arranged in a regular hexagon. The ideal modeling of the above scholars all have a certain influence on the experimental data.

Simple random arrangement of spherical energetic materials will result in large inter-particle gaps and low filling rate, which is far from the real charge process.

If the distance generated by spherical particles can be reasonably controlled during the placement process to reduce the gap, it will inevitably increase the number of particles filled, and the arrangement of the particles will be tighter; even if the distance between the particles is controlled, the gap between the particles still exists , if the compression chamber can be "shaked" by a certain method, the gap between the particles will be smaller, and a certain space will be vacated at the same time, it can continue to be placed, so that the filling rate can reach the highest.

Through the analysis of the existing domestic data, it is found that there is still a lack of methods to control the random placement process, intervene in the distance of particle generation and "shake" the compression chamber after placement, so as to try to place it again. The present invention proposes a simple and effective algorithm for solving the problem of low filling rate of spherical particles by analyzing the gap generated during actual filling. references

[1] Baer M R. Modeling heterogeneous energetic materials at the Mesoscale [J]. Thermochimica acta, 2002, 384: 351-367.

[2] Liu Qun, Chen Lang, Lu Jianying, etc. Numerical Simulation of Explosive Particle Compression Forming [J]. Journal of High Pressure Physics 2009, 23(6). DOI: 10.3969/j.issn.1000-5773.2009.

Contents of the invention

Aiming at the deficiencies of the existing technology, a displacement vector filling method based on the maximization of approximate spherical filling of energetic materials is proposed to increase the filling rate and improve the authenticity of the simulated data. The technical scheme of the present invention is as follows: a displacement vector filling method based on the approximate spherical filling of energetic materials, which comprises the following steps:

101. Randomly put spherical particles into the compression chamber according to the radius from large to small, and enter the adjustment stage after completing the spherical particle placement stage;

102. The adjustment stage is divided into three processes, establishing the x y z coordinate system, in which the x-axis and y-axis are the horizontal or vertical axes on the x-y plane, that is, the spherical particles move in the negative direction of the x-axis from small to large according to the x-axis coordinates , and then move to the negative direction of the y-axis from small to large in the y-axis coordinates, and finally move to the negative direction of the z-axis from small to large in the z-axis coordinates; process 1: use the x-axis coordinates to move all the spherical particles in the cabin to x The axis coordinate 0 is the origin, and the x-axis coordinates move from small to large in order to the negative direction of the x-axis.

103. Process 2: Take the 0 point of the y-axis coordinate as the origin, and move to the negative direction of the y-axis in order from small to large according to the y-axis coordinates;

104. Process 3: Finally, take the z-axis coordinate 0 as the origin, and move in the negative direction of the z-axis according to the z-axis coordinates from small to large, and do not intersect with any spherical particles after the movement is satisfied.

Further, the stage of placing spherical particles in step 101 is specifically:

Let the radius of the spherical particle be r ₁ , r ₂ , r ₃ ...... r _n , each time a spherical particle is placed, it will be compared with all the previous particles one by one, if it intersects with any particle, the placement will be discarded , if the gap with any particle is greater than d, give up this placement as well, and add 1 to the number of placement failures every time you give up placement; if the number of placement failures is greater than the maximum number of attempts, reduce the radius to r _m (1<m≤n) , n represents the number of n types of radii _, and the number of attempts is set to 0, and placed again, the successful placement should satisfy the following inequality:

Among them, r _p1,2 represents the size of the radius of any two particles, x _p1,2 represents the size of the x coordinate of the two particles, y _p1,2 represents the size of the y coordinate of the two particles, z _p1,2 represents the size of the z coordinate of the two particles, d represents the distance between any particles Maximum clearance.

Further, in step 102, the step of moving to the negative direction of the x-axis according to the coordinates of the x-axis from small to large is as follows: assuming that there are a total of n spherical particles in the compression cabin, the first moving distance is d ₁ , and the n-th The distance change of one movement is d _i , and d _i is the distance to try to move, which can be set according to specific experimental requirements. Generally, the smaller the better, it is sufficient not to intersect with any particles during the movement process. The movement method is: A1, The first particle moves from the position closest to the x-axis to the tangent to the x-axis, with a distance of d ₁ ; A2, the second to nth particles, try to move the spherical particles from small to large in order of x-axis coordinates , the moving distance is based on d ₁ , if it does not intersect with any particle after moving to the left, continue to move left with d _i as the decrement, otherwise stop moving, and satisfy the requirement that it does not intersect with any spherical particle after moving, and complete the movement towards the x-axis Move in negative direction.

Further, the step of moving to the negative direction of the y-axis according to the y-axis coordinates from small to large in step 103 is specifically: B1, move the first particle to be tangent to the y-axis, and the distance is _d1 ; B2, the second particle To the nth particle, try to move spherical particles from small to large in z-axis coordinates, and the moving distance is based on d _1. If it does not intersect with any particle after moving forward, continue to move down with d _i as the decrement. Otherwise, stop moving, and meet the requirement that it does not intersect with any spherical particles after moving, and complete the movement to the negative direction of the y-axis.

Further, in step 104, according to the z-axis coordinates from small to large, the method of moving in the negative direction of the z-axis is as follows: C1, move the first particle closest to the z-axis to be tangent to the z-axis, and the distance is _d1 ; C2 , from the second to the nth particle, try to move the spherical particle from small to large according to the z-axis coordinates, the moving distance is based on d ₁ , if it does not intersect with any particle after moving down, take d _i as the decrement Continue to move down, otherwise stop moving, and meet the requirement that it will not intersect with any spherical particles after moving, and move to the negative direction of the z-axis.

Advantage of the present invention and beneficial effect are as follows:

In the placement stage, every random particle generated will be next to the previously generated particles. This stage avoids the problem of large gaps caused by random particles being too far apart, and increases the number of particles filled;

In the adjustment stage, after the placement stage, there are still gaps between the particles. Through the horizontal movement of the particles on the x-axis and y-axis, the particles are more compact and the gaps are reduced, and then the downward movement on the z-axis further reduces the gaps and frees up the cabin space, which can be cycled into the placement stage to continue Filled with particles, thereby increasing the fill rate.

Description of drawings

Fig. 1 is a preferred embodiment of the present invention. Fig. 1 is a flow chart of a traditional algorithm for randomly placing spherical particles from large to small radii.

Fig. 2 is a flow chart of the filling algorithm of the improved filling stage proposed by the present invention.

Figure 3 is a flowchart of the entire algorithm, including the filling phase and the adjustment phase.

Figure 4 is a general filling schematic.

Fig. 5 is a schematic diagram of the filling completion of the inventive algorithm.

Figure 6 is a schematic diagram of the general filling.

Fig. 7 is a schematic diagram of the filling of the inventive algorithm.

Detailed ways

Below in conjunction with accompanying drawing, the present invention will be further described:

Referring to Fig. 1, Fig. 3 is the analysis process of the present invention, as shown in the figure, the present invention provides an algorithm based on the approximate spherical filling maximization of energetic materials, the algorithm includes a filling stage and an adjustment stage, and the steps are as follows:

Filling phase:

1. Randomly put spherical particles into the compression chamber according to the radius from large to small, set the radius as r ₁ , r ₂ , r ₃ ...... r _n , set the maximum number of attempts as 1 million times, the maximum The gap is d, p means spherical particles;

2. Every time a spherical particle (except the first one) is placed, it will be compared with all previous particles one by one. If it intersects with any particle, this placement will be abandoned. If the distance to any particle is greater than d, this time will also be abandoned. Placement, every time a placement is given up, the number of placement failures will increase by 1; if the number of placement failures is greater than the maximum number of attempts, change the radius to r _m (1<m≤n), set the number of attempts to 0, and place it again. Successful placement should satisfy the following inequality:

3. If the maximum number of placements is reached and the radius is r _n , the placement is complete and the program exits;

Adjustment phase:

4. Move all the spherical particles in the cabin to the x-axis coordinates as the origin, from small to large, in the negative direction of the x-axis. Suppose there are n spherical particles in the compressed cabin, and the distance of the first move is d ₁ . The distance change of the n-1th movement is d _i , and the movement method is:

4.1. The first particle (closest to the x-axis) moves to be tangent to the x-axis with a distance of d ₁ ;

4.2. From the 2nd to the nth particles, try to move the spherical particles from small to large in order of the x-axis coordinates. The moving distance is based on d _{1 .} The amount continues to move to the left, otherwise stop moving, and meet the requirement that it does not intersect with any spherical particle after moving;

5. After all the spherical particles are moved according to the above process, then move to the negative direction of the y-axis from small to large in the y-axis coordinates. The moving method is:

5.1. The first particle (closest to the y-axis) moves to be tangent to the y-axis with a distance of d ₁ ;

5.2 From the 2nd to the nth particle, try to move the spherical particle from small to large in order of the y-axis coordinates. The moving distance is based on d _1. If it does not intersect with any particle after moving forward, take d _i as the minus The amount continues to move forward, otherwise it stops moving, and meets the requirement that it does not intersect any spherical particles after moving;

6. After moving through the above process, move to the negative direction of the z-axis in order from small to large in z-axis coordinates. The moving method is:

5.1. The first particle (closest to the z-axis) moves to be tangent to the z-axis with a distance of d ₁ ;

5.2. From the 2nd to the nth particles, try to move the spherical particles from small to large according to the z-axis coordinates. The moving distance is based on d _{1 .} The amount continues to move down, otherwise stop moving, and meet the requirement that it will not intersect with any spherical particles after moving;

7. After the adjustment stage is completed, there will be a continuous blank area in the cabin, return to the filling stage, and continue to execute in order to achieve the maximum placement of spherical particles in the compressed cabin;

The above embodiments should be understood as only for illustrating the present invention but not for limiting the protection scope of the present invention. After reading the contents of the present invention, skilled persons can make various changes or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims (5)

1. A displacement vector filling method based on the approximate spherical filling of energetic material is characterized in that, comprising the following steps: 101. Randomly put spherical particles into the compression chamber according to the radius from large to small, and enter the adjustment stage after completing the spherical particle placement stage; 102. The adjustment stage is divided into three processes, establishing the x y z coordinate system, in which the x-axis and y-axis are the horizontal and vertical axes on the x-y plane, that is, the spherical particles move to the negative direction of the x-axis from small to large according to the x-axis coordinates , and then move to the negative direction of the y-axis from small to large in the y-axis coordinates, and finally move to the negative direction of the z-axis from small to large in the z-axis coordinates; process 1: use the x-axis coordinates to move all the spherical particles in the cabin to x The axis coordinate 0 is the origin, and the x-axis coordinates move from small to large in order to the negative direction of the x-axis. 103. Process 2: Take the 0 point of the y-axis coordinate as the origin, and move to the negative direction of the y-axis in order from small to large according to the y-axis coordinates; 104. Process 3: Finally, take the z-axis coordinate 0 as the origin, and move in the negative direction of the z-axis according to the z-axis coordinates from small to large, and do not intersect with any spherical particles after the movement is satisfied. 2. The displacement vector filling method based on the approximate spherical filling maximization of energetic materials according to claim 1, wherein the spherical particle placement stage in step 101 is specifically: Let the radius of the spherical particle be r ₁ , r ₂ , r ₃ ...... r _n , each time a spherical particle is placed, it will be compared with all the previous particles one by one, if it intersects with any particle, the placement will be discarded , if the gap with any particle is greater than d, give up this placement as well, and add 1 to the number of placement failures every time you give up placement; if the number of placement failures is greater than the maximum number of attempts, reduce the radius to r _m , 1<m≤n, n represents the number of n types of radii, and the number of attempts is set to 0, and placed again, the success of the placement should satisfy the following inequality: Among them, r _p1,2 represents the size of the radius of any two particles, x _p1,2 represents the size of the x coordinate of the two particles, y _p1,2 represents the size of the y coordinate of the two particles, z _p1,2 represents the size of the z coordinate of the two particles, d represents the distance between any particles Maximum clearance. 3. The displacement vector filling method based on the approximate spherical filling maximization of energetic materials according to claim 1, characterized in that, in step 102, the step of moving to the negative direction of the x-axis according to the x-axis coordinates from small to large is specifically : Assuming that there are n spherical particles in the compression chamber, the first moving distance is d ₁ , and the n-1th moving distance is the attempted moving distance d _i , _which can be set according to specific experimental requirements. The moving process It only needs to meet the requirement that it does not intersect with any particle, and the movement method is: A1, the first particle moves from the position closest to the x-axis to the tangent to the x-axis, and the distance is d ₁ ; A2, the second particle to the nth particles, the second particle is a particle that is close to the first particle on the x-axis coordinate, try to move the spherical particles from small to large on the x-axis coordinate, and the moving distance is based on d ₁ , if it does not match with If any particle intersects, continue to move to the left with d _i as the decrement, otherwise stop moving, and after satisfying the movement, it will not intersect with any spherical particle, and complete the movement to the negative direction of the x-axis. 4. The displacement vector filling method based on the approximate spherical filling maximization of energetic materials according to claim 3, characterized in that in step 103, the step of moving to the negative direction of the y-axis according to the y-axis coordinates from small to large is specifically : B1, move the first particle to be tangent to the y-axis, the distance is d ₁ ; B2, the second to the nth particle, the second particle is a particle close to the first particle in the y-axis coordinate, Try to move the spherical particles from small to large in the y-axis coordinates. The moving distance is based on d _1. If it does not intersect with any particle after moving forward, continue to move forward with d _i as the decrement. Otherwise, stop moving forward. And it is satisfied that it does not intersect with any spherical particle after moving, and moves to the negative direction of the y-axis. 5. The displacement vector filling method based on the approximate spherical filling maximization of energetic materials according to claim 3, characterized in that in step 104, according to the z-axis coordinates from small to large, the method of moving to the negative direction of the z-axis is specifically: C1. Move the first particle closest to the z-axis to be tangent to the z-axis at a distance of _d1 ; C2. From the second to the nth particle, the second particle is at the z-axis coordinate with the first particle For similar particles, try to move the spherical particles from small to large in z-axis coordinates. The moving distance is based on d _1. If it does not intersect with any particle after moving down, continue to move down with d _i as the decrement, otherwise stop Move, and meet the requirement that the movement does not intersect with any spherical particles, and complete the movement to the negative direction of the z-axis.