Columnar charge lightweight design method for damaging reinforced concrete column

Abstract

The invention discloses a cylindrical charge lightweight design method for damaging a reinforced concrete column. The cylindrical charge lightweight design method comprises the steps that 1, structural characteristic parameters and bearing characteristic parameters of the hit reinforced concrete column are set; 2, selecting a charging type, determining charging material model parameters, and giving charging striking precision and a detonation mode; 3, cylindrical charging design constraint conditions are set; 4, according to the cylindrical charging constraint conditions, cylindrical charging parameters meeting the constraint condition requirements are generated in batches, and according to different constraint condition setting modes in the step 3, cylindrical charging parameter batch generation methods are different; step 5, carrying out charge lightweight design simulation; and step 6, counting simulation results, and screening out charge lightweight design results. According to the method, a small charging structure is designed in a customized mode according to the damage state of the column, and a lightweight design result meeting the damage requirement can be given under a series of charging size design constraint conditions.

Description

[0001] The invention belongs to the field of damage technology, and specifically relates to a lightweight design method for blasting charges, in particular to a lightweight design method for columnar charges used to damage reinforced concrete columns. Background Art

[0002] Reinforced concrete columns are the core load-bearing components of building targets. Effective damage to multiple reinforced concrete columns in a building system may cause the building to collapse. With the development of miniaturized cluster unmanned platforms, using "swarms" to attack reinforced concrete columns to induce the collapse of the entire building is a potential and effective way for cluster platforms to attack buildings.

[0003] According to the survey, the current miniaturized cluster unmanned platform can only carry a kilogram-level payload, but reinforced concrete columns are typical solid targets, and small charges can only have a certain damaging effect on reinforced concrete columns when the distance is relatively close. Taking into account the load requirements and endurance requirements of the cluster platform, the charge shape should be reasonably designed to fully regulate the damage ability of the charge to the reinforced concrete column to meet the requirements of miniaturization and lightweight design of the charge. At present, there is no lightweight design method for blasting charges that can support the damage of reinforced concrete columns. Summary of the invention

[0004] In order to overcome the problem of lack of lightweight design of small charges in the prior art, the present invention provides a lightweight design method of columnar charges for damaging reinforced concrete columns. This method can customize and lightweight design of columnar blasting charges that meet the damage requirements according to the specific structural characteristics and bearing characteristics of reinforced concrete columns.

[0005] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0006] A lightweight design method for cylindrical charges for damaging reinforced concrete columns comprises the following steps:

[0007] Step 1: Set the structural characteristic parameters and bearing characteristic parameters of the reinforced concrete column to be struck;

[0008] Step 2: Select the charge type, determine the charge material model parameters, and give the charge strike accuracy and detonation method;

[0009] Step 3: Set the design constraints of the cylindrical charge. The parameters of the constraints that can be set include charge length L, charge diameter D, charge length-to-diameter ratio LDR, and charge mass M.

[0010] Step 4: According to the constraint conditions of the column charge, batch-generate column charge parameters that meet the constraint conditions. The batch generation method of column charge parameters is different according to the different setting methods of the constraint conditions in step 3;

[0011] Step 5: Carry out charge lightweight design simulation, including the following steps:

[0012] Step 5.1: Select any set of column charge parameters in step 4;

[0013] Step 5.2: Establish a numerical simulation model of reinforced concrete column preloaded with axial compression through LS-DYNA pre-processing; the components in the model should include reinforced concrete column, axial compression loading rod, and gasket;

[0014] Step 5.3: According to the axial static load of the reinforced concrete column, apply a constant axial pressure to the reinforced concrete column until the internal force of the structure is balanced;

[0015] Step 5.4: Conduct a full restart analysis based on the simulation results in step 5.2, adding air and explosive components;

[0016] Step 5.5: Detonate the explosive charge, continuously observe the damage state of the reinforced concrete column, determine whether the reinforced concrete column is crushed, and record the simulation results. The simulation results include "the column is crushed" or "the column is not crushed";

[0017] Among them, the simulation result of "the column is crushed" means that the column is axially unstable under the simultaneous action of axial pressure and explosion load; the simulation result of "the column is not crushed" means that the column remains axially stable under the simultaneous action of axial pressure and explosion load;

[0018] Step 5.6: Determine whether all the columnar charge parameters in step 4 are currently traversed; if they have been completely traversed, end step 5; if they have not been completely traversed, return to step 5.1;

[0019] Step 6: Count the simulation results and select the lightweight design results of the charge. In the "column is crushed" condition, select the charge with the smallest weight as the lightweight design result.

[0020] The lightweight design method of columnar charge for damaging reinforced concrete columns of the present invention has the following technical effects:

[0021] The present invention realizes customized design of small charge structure according to the damage state of the column ("column is crushed" or "column is not crushed"), and can provide lightweight design results that meet the damage requirements under a series of charge size design constraints, thereby effectively reducing the mass redundancy of the charge used to damage reinforced concrete columns and improving the energy utilization rate of charge damage. The present invention can support the development of small warheads for building damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of a lightweight design method of a columnar charge for damaging a reinforced concrete column of the present invention;

[0023] Figure 2 Schematic diagram of a numerical simulation model of preloaded axial compression of reinforced concrete columns in an embodiment;

[0024] Figure 3 : is the structural axial stress distribution diagram at the initial moment and after 50ms of pre-axial pressure in the embodiment;

[0025] Figure 4 is a graph showing the variation trend of the mid-span axial pressure of the structure over time during the pre-axial pressure process in the embodiment;

[0026] Figure 5 is a schematic diagram of a simulation model after adding air and explosives after a complete restart analysis in an embodiment;

[0027] Figure 6 1 is a simulation result diagram of three charging parameter working conditions in the embodiment, where (a) is 1 kg, not crushed, (b) is 1.2 kg, not crushed, and (c) is 1.4 kg, crushed; DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0029] like Figure 1 As shown, the lightweight design method of columnar charge for damaging reinforced concrete columns provided by the present invention comprises the following steps:

[0030] Step 1: Set the structural characteristic parameters and bearing characteristic parameters of the reinforced concrete column to be struck;

[0031] The structural characteristic parameters of reinforced concrete columns include length, width, height, longitudinal reinforcement diameter, number of longitudinal reinforcements, stirrup diameter, stirrup spacing, sheath thickness, concrete uniaxial compressive strength, and steel yield strength;

[0032] The load-bearing characteristic parameters of reinforced concrete columns refer to their axial static load;

[0033] Step 2: Select the charge type, determine the charge material model parameters, and give the charge strike accuracy and detonation method;

[0034] Step 3: Set the design constraints of the cylindrical charge. The parameters of the constraints that can be set include charge length L, charge diameter D, charge aspect ratio LDR and charge mass M. The constraints can be set in the following two ways:

[0035] Method 1: Set the range of charge length L and charge diameter D as design constraints at the same time.

[0036] Charge length constraint: L min ≤L≤L max , where L min , L maxare the minimum and maximum values ​​of charge length respectively;

[0037] Charge diameter constraint: D min ≤D≤D max , where D min , D max are the minimum and maximum values ​​of charge diameter, respectively;

[0038] Method 2: Simultaneously set the range of charge length-to-diameter ratio LDRL and charge mass MM as design constraints.

[0039] Charge length-to-diameter ratio constraint: LDR min ≤LDR≤LDR max , where LDR min , LDR max are the minimum and maximum values ​​of the charge aspect ratio, respectively;

[0040] Charge mass constraint: M min ≤M≤M max , where M min 、M max are the minimum and maximum values ​​of the charge mass respectively;

[0041] Step 4: According to the constraints of the column charge, batch generate column charge parameters that meet the constraints. The batch generation method of column charge parameters is different according to the different setting methods of the constraints in step 3:

[0042] For method 1, according to the charge length constraint L min ≤L≤L max and charge diameter constraint D min ≤D≤D max Customize and generate m charge length samples L1, L2, L3, ..., L m and n charge diameter samples D1, D2, D3, ..., D n , the sample should meet the following requirements:

[0043]

[0044] Then, the parameters in the charge length sample and the charge diameter sample are arbitrarily combined to form m×n groups of cylindrical charge size parameters (L i ,D j ), where 1≤i≤m, 1≤j≤n;

[0045] For method 2, according to the charge length-to-diameter ratio constraint LDR min ≤LDR≤LDR max and charge mass constraint M min ≤M≤M maxCustomize and generate m charge length-to-diameter ratio samples LDR1, LDR2, LDR3, ..., LDR m and n charge mass samples M1, M2, M3, ..., M n , the sample should meet the following requirements:

[0046]

[0047] Then, the parameters in the charge aspect ratio sample and charge mass sample are arbitrarily combined to form m×n groups of columnar charge parameters (LDR i ,M j ), where 1≤i≤m, 1≤j≤n, further, according to the column charge parameter (LDR i ,M j ) Calculate the charge diameter D and charge length L:

[0048]

[0049] Step 5: Carry out charge lightweight design simulation, including the following steps:

[0050] Step 5.1: Select any set of column charge parameters in step 4;

[0051] Step 5.2: Establish a numerical simulation model of reinforced concrete column preloaded with axial compression through LS-DYNA pre-processing; the components in the model should include reinforced concrete column, axial compression loading rod, and gasket;

[0052] Step 5.3: According to the axial static load of the reinforced concrete column, apply a constant axial pressure to the reinforced concrete column until the internal force of the structure is balanced;

[0053] Step 5.4: Conduct a full restart analysis based on the simulation results in step 5.3, adding air and explosive components;

[0054] Step 5.5: Detonate the explosive charge, continuously observe the damage state of the reinforced concrete column, determine whether the reinforced concrete column is crushed, and record the simulation results. The simulation results include "the column is crushed" or "the column is not crushed";

[0055] Among them, the simulation result of "the column is crushed" means that the column is axially unstable under the simultaneous action of axial pressure and explosion load; the simulation result of "the column is not crushed" means that the column still maintains axial stability under the simultaneous action of axial pressure and explosion load.

[0056] Step 5.6: Determine whether all the columnar charge parameters in step 4 are currently traversed; if they have been completely traversed, end step 5; if they have not been completely traversed, return to step 5.1;

[0057] Step 6: Count the simulation results and select the lightweight design results of the charge. In the "column is crushed" condition, select the charge with the smallest weight as the lightweight design result.

[0058] The present invention is further described in detail below through specific examples.

[0059] Embodiment 1:

[0060] Step 1: Set the structural characteristic parameters and bearing characteristic parameters of the reinforced concrete column to be struck;

[0061] The structural characteristic parameters of reinforced concrete columns include length, width, height, longitudinal reinforcement diameter, number of longitudinal reinforcements, stirrup diameter, stirrup spacing, sheath thickness, concrete uniaxial compressive strength, and steel yield strength;

[0062] The load-bearing characteristic parameters of reinforced concrete columns refer to their axial static load;

[0063] This example uses a typical scaled reinforced concrete column as the research object. The reinforced concrete column is 1900 mm long, 200 mm wide, and 200 mm high. The diameter of the longitudinal reinforcement is The number of longitudinal bars is 8 and the diameter of stirrups is The stirrup spacing is 100mm, the covering layer thickness is 25mm, the concrete specification is C40, the concrete compressive strength is 40MPa, the steel bar specification is HRB400, and the yield strength is 400MPa.

[0064] The axial static load of the reinforced concrete column is set to 320 kN.

[0065] Step 2: Select the charge type, determine the charge material model parameters, and give the charge strike accuracy and detonation method;

[0066] In this implementation, the charge type is set to TNT, and the detonation and shock wave propagation process of TNT explosives is described by the *MAT_HIGH_EXPLOSIVE_BURN material model and the *EOS_JWL state equation. The explosive material model parameters are shown in the following table. CJ , P CJ These are parameters related to the *MAT_HIGH_EXPLOSIVE_BURN material model. All other parameters are related to the *EOS_JWL equation of state.

[0067] Table 1 Charge material model parameters in the embodiment

[0068]

[0069] In this embodiment, the detonation method is single-point detonation at the center of the upper end surface of the charge, and the strike accuracy is set to 0.2m.

[0070] Step 3: Set the design constraints of the columnar charge. The parameters of the constraints that can be set include charge length L, charge diameter D, charge length-to-diameter ratio LDR and charge mass M. There are two ways to set the constraints. In this embodiment, the constraint is set in method 2. The charge length-to-diameter ratio constraint is LDR. min =0.5, LDR max =0.5, the charge mass constraint is M min =1kg, M max =1.4kg.

[0071] Step 4: According to the columnar charge constraint conditions, batch generate columnar charge parameters that meet the constraint conditions. According to the different setting methods of the constraint conditions in step 3, there are two batch generation methods for columnar charge parameters. In this embodiment, method 2 is adopted to batch generate columnar charge parameters. According to the charge aspect ratio constraint condition 0.5≤LDR≤0.5 and the charge mass constraint condition 1≤M≤1.4, a charge aspect ratio sample LDR1 and three charge mass samples M1=1, M2=1.2, M3=1.4 are generated by self-defined. The samples meet the following requirements:

[0072]

[0073] Then, the parameters in the charge aspect ratio sample and charge mass sample are arbitrarily combined to form 1×3 groups of columnar charge parameters (LDR i ,M j ), where 1≤i≤1, 1≤j≤3, further, according to the column charge parameter (LDR i ,M j ) Calculate the charge diameter D and charge length L:

[0074]

[0075] The following table lists all the cylindrical charge parameters generated in batches.

[0076] Table 2 List of columnar charge parameters formed according to constraints in the embodiment

[0077] Charge parameter conditions Charge aspect ratio Charge mass / kg Charge length / mm Charge diameter / mm 1 0.5 1 58.03 116.08 2 0.5 1.2 61.68 123.34 3 0.5 1.4 64.92 129.85

[0078] Step 5: Carry out charge lightweight design simulation, including the following steps:

[0079] Step 5.1: Select any set of column charge parameters in step 4;

[0080] Step 5.2: Use LS-DYNA pre-processing to establish a numerical simulation model of reinforced concrete columns with preloaded axial pressure. The components in the model should include reinforced concrete columns, axial pressure loading rods, and gaskets. The simulation model is as follows: Figure 2As shown, all nodes in region A are subject to full-degree-of-freedom constraints, all nodes in region B are subject to all-degree-of-freedom constraints except the axial displacement of the column, and the axial pressure is applied to the end of the loading rod;

[0081] Step 5.3: According to the axial static load of the reinforced concrete column, a constant axial pressure of 320 kN is applied to the reinforced concrete column until the internal force of the structure is balanced. In this embodiment, the axial pressure is applied for 50 ms. Figure 3 (a) and (b) show the axial stress distribution diagrams at the initial moment and 50ms respectively. Figure 4 The variation of the axial pressure in the mid-span of the structure is given. Figure 3 , Figure 4 It can be seen that the structural axial force is evenly distributed at 50ms;

[0082] Step 5.4: Based on the simulation results in step 5.3, perform a full restart analysis and add air and explosive components, such as Figure 5 As shown;

[0083] Step 5.5: Detonate the explosive charge, continuously observe the damage state of the reinforced concrete column, determine whether the reinforced concrete column is crushed, and record the simulation results. The simulation results include "the column is crushed" or "the column is not crushed";

[0084] Step 5.6: Determine whether all the columnar charge parameters in step 4 are currently traversed; if they have been completely traversed, end step 5; if they have not been completely traversed, return to step 5.1;

[0085] Step 6: Count the simulation results and select the lightweight design results of the charge. In the "column is crushed" condition, select the charge with the smallest weight as the lightweight design result.

[0086] Figure 6 The crushing state of the column is given when the charge mass is 1kg, 1.2kg and 1.4kg. When the charge mass is 1.4kg, the reinforced concrete column is crushed. Therefore, the lightweight design result of the cylindrical charge is that the charge mass is 1.4kg, the charge diameter is 129.85mm, and the charge length is 64.92mm.

Claims

1. A lightweight design method for columnar charges used to damage reinforced concrete columns, characterized in that: The steps include: Step 1: Set the structural characteristic parameters and bearing characteristic parameters of the reinforced concrete column to be struck; Step 2: Select the charge type, determine the charge material model parameters, and give the charge strike accuracy and detonation method; Step 3: Set the design constraints of the cylindrical charge. The parameters of the constraints that can be set include charge length L, charge diameter D, charge length-to-diameter ratio LDR, and charge mass M. Step 4: According to the constraint conditions of the column charge, batch-generate column charge parameters that meet the constraint conditions. The batch generation method of column charge parameters is different according to the different setting methods of the constraint conditions in step 3; Step 5: Carry out charge lightweight design simulation, including the following steps: Step 5.1: Select any set of column charge parameters in step 4; Step 5.2: Establish a numerical simulation model of reinforced concrete column preloaded with axial compression through LS-DYNA pre-processing; the components in the model should include reinforced concrete column, axial compression loading rod, and gasket; Step 5.3: According to the axial static load of the reinforced concrete column, apply a constant axial pressure to the reinforced concrete column until the internal force of the structure is balanced; Step 5.4: Perform a full restart analysis, adding air and explosive components; Step 5.5: Detonate the explosive charge, continuously observe the damage state of the reinforced concrete column, determine whether the reinforced concrete column is crushed, and record the simulation results. The simulation results include "the column is crushed" or "the column is not crushed"; Among them, the simulation result of "the column is crushed" means that the column is axially unstable under the simultaneous action of axial pressure and explosion load; the simulation result of "the column is not crushed" means that the column remains axially stable under the simultaneous action of axial pressure and explosion load; Step 5.6: Determine whether all the columnar charge parameters in step 4 are currently traversed; if they have been completely traversed, end step 5; if they have not been completely traversed, return to step 5.1; Step 6: Count the simulation results and select the lightweight design results of the charge. In the "column is crushed" condition, select the charge with the smallest weight as the lightweight design result.

2. The lightweight design method for columnar charges for damaging reinforced concrete columns according to claim 1, characterized in that: In step 1, the structural characteristic parameters of the reinforced concrete column include length, width, height, longitudinal reinforcement diameter, number of longitudinal reinforcements, stirrup diameter, stirrup spacing, coating thickness, concrete uniaxial compressive strength and steel yield strength; the bearing characteristic parameters of the reinforced concrete column refer to its axial static load.

3. The lightweight design method for columnar charges for damaging reinforced concrete columns according to claim 2, characterized in that: In step 3, there are two ways to set constraints: Method 1: Set the range of charge length L and charge diameter D as design constraints at the same time; Charge length constraint: L min ≤L≤L max , where L min , L max are the minimum and maximum values ​​of charge length respectively; Charge diameter constraint: D min ≤D≤D max , where D min , D max are the minimum and maximum values ​​of charge diameter, respectively; Method 2: Set the range of charge length-to-diameter ratio LDRL and charge mass MM as design constraints at the same time; Charge length-to-diameter ratio constraint: LDR min ≤LDR≤LDR max , where LDR min , LDR max are the minimum and maximum values ​​of the charge aspect ratio, respectively; Charge mass constraint: M min ≤M≤M max , where M min 、M max are the minimum and maximum values ​​of the charge mass, respectively.

4. The lightweight design method for columnar charges for damaging reinforced concrete columns according to claim 3, characterized in that: In step 4, for method 1, according to the charge length constraint L min ≤L≤L max and charge diameter constraint D min ≤D≤D max Customize and generate m charge length samples L1, L2, L3, ..., L m and n charge diameter samples D1, D2, D3, ..., D n , the sample should meet the following requirements: Then, the parameters in the charge length sample and the charge diameter sample are arbitrarily combined to form m×n groups of cylindrical charge size parameters (L i ,D j ), where 1≤i≤m, 1≤j≤n; For method 2, according to the charge length-to-diameter ratio constraint LDR min ≤LDR≤LDR max and charge mass constraint M min ≤M≤M max Customize and generate m charge length-to-diameter ratio samples LDR1, LDR2, LDR3, ..., LDR m and n charge mass samples M1, M2, M3, ..., M n , the sample should meet the following requirements: Then, the parameters in the charge aspect ratio sample and charge mass sample are arbitrarily combined to form m×n groups of columnar charge parameters (LDR i ,M j ), where 1≤i≤m, 1≤j≤n, further, according to the column charge parameter (LDR i ,M j ) Calculate the charge diameter D and charge length L:

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