Electro-structural coupling seismic damage assessment method

Abstract

The present application relates to the technical field of building structure seismic evaluation, and more particularly to a kind of electrical-structure coupling seismic damage evaluation method, including the establishment of reinforced concrete main structure, electrical equipment and pipeline coupling finite element model;Reinforced concrete main structure, electrical equipment and pipeline damage factor definition;Damage weight coefficient confirmation;Coupling damage area division;Based on the weighted sum of defined damage factor and corresponding weight coefficient, calculate coupling damage comprehensive factor, and divide damage grade and propose repair strategy.The present application breaks through the limitation of traditional method ignoring the feedback effect of equipment pipeline, realizes the unified damage evaluation and quantitative decision of structure-equipment-pipeline system, effectively reduces the detection repair cost, especially suitable for substation, data center, hospital and other function sensitive building scenes, with high engineering application value.

Description

Technical Field

[0001] This invention relates to the field of seismic assessment technology for building structures, and more particularly to a method for assessing damage to electrical-structural coupled seismic resistance. Background Technology

[0002] Following an earthquake, the ability of a building structure to rapidly recover its functionality has become a crucial indicator for building resilient cities. Traditional seismic design and damage assessment methods primarily focus on the mechanical response of load-bearing components such as beams, columns, and joints in reinforced concrete structures, prioritizing structural collapse safety and human life safety. However, modern buildings contain a vast number of electrical equipment and widely distributed pipeline systems, and damage to these systems during earthquakes often directly leads to building dysfunction, causing significant indirect economic losses. For example, in functionally sensitive buildings such as substations, data centers, and hospitals, even if the main structure does not collapse, damage to electrical equipment and pipelines can result in power outages or emergency system failures, severely impacting post-earthquake recovery.

[0003] Existing seismic assessment methods have the following shortcomings: First, they ignore the feedback effect of the mass, stiffness, and constraints of equipment and pipelines on the main structure, and cannot truly reflect the seismic response of the coupled system; second, they lack a unified damage index, and different criteria are used for structures, equipment, and pipelines, making comprehensive assessment difficult; third, the weighting coefficients are mostly determined by experience, and the full life cycle cost and repair difficulty are not fully considered; and fourth, the coupled damage area is not clearly delineated, which cannot guide targeted repair.

[0004] Therefore, it is necessary to provide a new electrical-structural coupled seismic damage assessment method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The main objective of this invention is to provide a damage assessment method for electrical-structural coupling seismic resistance, aiming to solve the technical problem that existing seismic assessment methods cannot accurately reflect the seismic response of the coupled system and carry out targeted repairs.

[0006] To achieve the above objectives, the present invention proposes a damage assessment method for electrical-structural coupling seismic resistance, comprising the following steps: S1. Based on the feedback effect of the mass, stiffness, constraint and contact of electrical equipment on the dynamic response of the main structure, establish a coupled finite element model of the reinforced concrete main structure, electrical equipment and pipelines; S2. Damage factors for reinforced concrete main structures, electrical equipment and pipelines are defined as follows: damage factors for reinforced concrete main structures, electrical equipment and pipelines are constructed based on damage index, peak acceleration at the top and relative rotation angle of pipelines, respectively. S3. Confirmation of damage weight coefficients: Specifically, under the coupled seismic system, based on the full life cycle cost and repair difficulty, the damage weight coefficients of the reinforced concrete main structure, electrical equipment and pipelines corresponding to the damage factors defined in S2 are determined respectively. S4. Division of coupled damage regions: In the coupled finite element model established in S1, input the actual earthquake action, and determine multiple coupled damage regions with potential severe damage based on the damage index of concrete and the stress of steel bars. S5. Based on the weighted summation of the damage factor defined in S2 and the corresponding weight coefficients in S3, calculate the coupled damage comprehensive factor, classify the damage level, and propose repair strategies.

[0007] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention is that the coupled finite element model treats electrical equipment as a multi-mass system, and pipelines as beam elements based on axial stiffness and bending stiffness. The anchoring effect of electrical equipment, pipelines and reinforced concrete main structure is simulated through rigid connections or spring elements, and seismic motion time history analysis is performed simultaneously based on the coupled finite element model.

[0008] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention is that the damage factor of the reinforced concrete main structure is calculated based on the Park-Ang method, and the calculation formula is as follows: ; in: For the damage factors of reinforced concrete main structures, For displacement, For the ultimate displacement, This is the energy consumption weighting coefficient. To accumulate energy consumption, It represents the yield strength.

[0009] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention is that the damage factor of electrical equipment is calculated based on the peak acceleration at the top of the equipment, as shown in the following formula: ; in: Damage factors for electrical equipment The allowable acceleration at the top of the electrical equipment. This refers to the acceleration of the top of electrical equipment during an earthquake.

[0010] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention is that the damage factor of the pipeline is calculated based on the relative rotation angle of the pipeline, as shown in the following formula: ; in: Damage factors for pipelines, For the allowable relative angle of the pipeline, The angle of the pipeline is the angle between the input pipeline and the output pipeline.

[0011] A further improvement of the electrical-structural coupling seismic damage assessment method of the present invention lies in its ability to reduce repair difficulty. The expression is as follows: ; in: For the fixed coefficient of repair time, To change the fixed coefficient of difficulty, For the fixed coefficient of the repair process, satisfy ; The time-consuming and difficult repair process To change the difficulty level. The difficulty level of the repair process.

[0012] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention lies in the damage weighting coefficient. The expression is as follows: ; in, The total lifecycle cost of the main structure, electrical equipment, or pipelines. The total life-cycle cost of the main structure, For the total life cycle cost of electrical equipment, For the total life cycle cost of the pipeline, The difficulty of repairing the main structure, pipelines, or electrical equipment.

[0013] A further improvement of the electrical-structural coupling seismic damage assessment method of the present invention is that, when determining multiple potential severe damage coupled damage areas, the seismic motion is first input into the coupled finite element model. When the stress of the main reinforcing bar reaches the yield strength and the damage index of the concrete reaches 0.6 or above, the area is initially determined as a single potential area of ​​severe coupled damage. Then, the damage factors of electrical equipment and pipelines in the determined multiple potential areas of severe coupled damage are calculated respectively, and the comprehensive factor of coupled damage is calculated to assess the weak areas in the structure.

[0014] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention lies in the coupling damage comprehensive factor of the coupled damage region. The expression is as follows: ; in: The damage weighting coefficient for the main structure. For damage weighting coefficients of electrical equipment, This is the damage weighting coefficient for the pipeline.

[0015] A further improvement of the electrical-structural coupled seismic damage assessment method of the present invention is that the damage level is classified according to the following criteria: if the coupled damage comprehensive factor If the value is less than 0.1, it is determined that no repair is needed; if 0.1 ≤ If the value is ≤0.65, it is determined that repair is needed and the device can continue to be used after repair; if If the value is greater than 0.65, it is determined that the repair is impossible.

[0016] The technical solution of the present invention has the following beneficial effects: The electrical-structural coupled seismic damage assessment method provided by this invention establishes a coupled finite element model of the main structure, electrical equipment, and pipelines. It fully considers the feedback effects of equipment mass, stiffness, constraints, and contact on the dynamic response of the main structure, overcoming the limitation of traditional methods that treat equipment merely as an added mass, and significantly improving the simulation accuracy of seismic response. Three types of sub-damage factors are constructed based on the Park-Ang damage index, peak ground acceleration, and pipeline relative rotation angle, respectively. A weighted summation method is used to calculate the coupled damage comprehensive factor, solving the problem of inconsistent damage criteria and difficulty in comprehensive assessment for different types of components. Damage weight coefficients are determined based on life-cycle cost and repair difficulty, which is more objective and economically oriented than traditional empirical scoring. The assessment results can be directly used for post-earthquake repair priority ranking. Potentially severe damage areas are initially delineated by simultaneously satisfying the conditions of main reinforcement yield and concrete damage index ≥ 0.6. Further confirmation of truly weak areas is achieved by combining the damage factors of equipment and pipelines, effectively avoiding "overall inspection and blind repair," and significantly reducing inspection and repair costs. Based on the numerical range of the coupled damage comprehensive factor, three repair levels are defined (no repair required, repair required and can be used after repair, and repair impossible). This provides a quantitative basis for rapid decision-making after an earthquake, effectively improves the seismic resilience assessment level of functionally sensitive buildings (such as substations, data centers, hospitals, etc.), effectively ensures the restoration of power supply and emergency functions after an earthquake, and protects the safety of people's lives and property. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1This is a flowchart of the electrical-structural coupling seismic damage assessment method of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0024] like Figure 1As shown, this invention proposes a damage assessment method for electrical-structural coupled seismic resistance. By establishing a coupled finite element model of the main structure, electrical equipment, and pipelines, three types of damage factors are defined. Weighting coefficients are determined based on life-cycle cost and repair difficulty. Severely damaged coupled areas are identified, and a comprehensive coupled damage factor is calculated to classify damage levels and repair strategies. This method can more realistically assess the overall damage state of the structure-equipment-pipeline system after an earthquake, providing a scientific basis for the life-cycle seismic design and rapid post-earthquake repair of functionally sensitive buildings. The method includes the following steps: S1. Based on the feedback effect of the mass, stiffness, constraint and contact of electrical equipment on the dynamic response of the main structure, establish a coupled finite element model of the reinforced concrete main structure, electrical equipment and pipelines; S2. Damage factors for reinforced concrete main structures, electrical equipment and pipelines are defined as follows: damage factors for reinforced concrete main structures, electrical equipment and pipelines are constructed based on damage index, peak acceleration at the top and relative rotation angle of pipelines, respectively. S3. Confirmation of damage weight coefficients: Specifically, under the coupled seismic system, based on the full life cycle cost and repair difficulty, the damage weight coefficients of the reinforced concrete main structure, electrical equipment and pipelines corresponding to the damage factors defined in S2 are determined respectively. S4. Division of coupled damage regions: In the coupled finite element model established in S1, input the actual earthquake action, and determine multiple coupled damage regions with potential severe damage based on the damage index of concrete and the stress of steel bars. S5. Based on the weighted summation of the damage factor defined in S2 and the corresponding weight coefficients in S3, calculate the coupled damage comprehensive factor, classify the damage level, and propose repair strategies.

[0025] Specifically, the coupled finite element model treats electrical equipment as a multi-mass system, pipelines as beam elements based on axial stiffness and bending stiffness, simulates the anchoring effect of electrical equipment, pipelines and reinforced concrete main structure through rigid connections or spring elements, and performs seismic time history analysis simultaneously based on the coupled finite element model.

[0026] Furthermore, the damage factor of the reinforced concrete main structure is calculated based on the Park-Ang method, and the calculation formula is as follows: ; in: For the damage factors of reinforced concrete main structures, For displacement, For the ultimate displacement, This is the energy consumption weighting coefficient. To accumulate energy consumption, The value represents the yield strength. In the main structure, only damage to beams, columns, and nodes is considered. In engineering practice, finite element models of actual beams, columns, and nodes need to be established separately to confirm the change process of their damage indices. In actual engineering, the displacement time history and cumulative energy dissipation of each component can be extracted through finite element time history analysis and substituted into the formula to calculate the damage index.

[0027] Specifically, the damage factor of electrical equipment is calculated based on the peak acceleration at the top of the equipment, as shown in the following formula: ; in: Damage factors for electrical equipment The allowable acceleration at the top of electrical equipment is generally determined and given by the manufacturer through multiple rounds of testing; The acceleration at the top of electrical equipment during an earthquake can be extracted using time history analysis.

[0028] Specifically, the damage factor of the pipeline is calculated based on the relative bend angle of the pipeline, as shown in the following formula: ; in: Damage factors for pipelines, The allowable relative angle of the pipeline is determined based on factors such as impact on the normal use of the pipeline and excessive line deformation. The angle of the pipeline is the angle between the input pipeline and the output pipeline.

[0029] Furthermore, the damage weighting coefficient is determined based on the total life cycle cost and the difficulty of repair; the total life cycle cost includes the initial cost, maintenance cost, and repair cost after damage; the difficulty of repair includes the repair procedures, repair time, and replacement difficulty.

[0030] Specifically, the difficulty of repair The expression is as follows: ; in: For the fixed coefficient of repair time, To change the fixed coefficient of difficulty, The fixed coefficient for the repair process is mainly determined based on the application requirements of the project and the needs of the client, etc., to meet the requirements. ; The time-consuming and difficult repair process To change the difficulty level. The difficulty level of the repair process can be divided into three levels: relatively easy to repair, relatively difficult to repair, and difficult to repair, with coefficients of 0.6, 0.8, and 1.0, respectively.

[0031] Specifically, damage weighting coefficient The expression is as follows: ; in, The total lifecycle cost of the main structure, electrical equipment, or pipelines. The total life-cycle cost of the main structure, For the total life cycle cost of electrical equipment, For the total life cycle cost of the pipeline, The difficulty of repairing the main structure, pipelines, or electrical equipment.

[0032] Specifically, when identifying coupled damage regions with multiple potential severe damages, real ground vibrations are first input into the coupled finite element model. If both the stress in the main reinforcing bars reaches the yield strength and the damage index of the concrete reaches 0.6 or higher, this region is preliminarily identified as a single potential coupled severe damage region. Then, the damage factors of electrical equipment and pipelines in the identified multiple potential coupled severe damage regions are calculated separately. Finally, the combined coupled damage factor is calculated to assess the true weak areas within the structure. The three regions with the largest combined coupled damage factors are identified as the true weak areas.

[0033] Furthermore, the concrete damage index is calculated based on the concrete damage index calculation formula in the appendix of the national standard "Standard for Design of Concrete Structures" GB / T 50010-2010; it can be calculated using the CDP model of ABAQUS and can be directly displayed and read in the finite element model.

[0034] Specifically, the coupling damage synthesis factor of the coupling damage region. The expression is as follows: ; in: The damage weighting coefficient for the main structure. For damage weighting coefficients of electrical equipment, This is the damage weighting coefficient for the pipeline.

[0035] Specifically, the damage level is classified according to the following criteria: if coupled with a comprehensive damage factor... If the value is less than 0.1, it is determined that no repair is needed; if 0.1 ≤ If the value is ≤0.65, it is determined that repair is needed and the device can continue to be used after repair; if If the value is greater than 0.65, it is determined that the repair is impossible.

[0036] Traditional assessment methods only evaluate the load-bearing components of the main structure, ignoring the coupling feedback effect of electrical and pipeline systems on the main structure. This leads to inconsistent damage criteria for structures, equipment, and pipelines. Weighting coefficients rely on manual experience, failing to accurately locate the coupled damage areas of the structure-equipment-pipeline system, resulting in significant assessment bias and uninformed repair decisions. In contrast, this invention constructs a coupled finite element model of the three systems, unifies and quantifies damage factors, objectively weights damage based on life-cycle cost and repair difficulty, accurately delineates coupled damage areas, and quantifies the comprehensive damage level, achieving accurate assessment of the entire system. The following table compares the traditional assessment methods with the method of this invention:

[0037] 1. Simulation Accuracy: Traditional methods treat electrical and pipeline systems as merely additional mass, neglecting their stiffness and constraints on the main structure, resulting in significant deviations between the model and the actual stress state in engineering projects. This invention uses equivalent equipment in a multi-mass system and equivalent pipelines in beam elements, combined with spring / rigid connections to simulate anchorage coupling relationships, to simultaneously perform seismic motion time history analysis, greatly aligning with the actual stress state and significantly improving simulation realism.

[0038] 2. Comprehensive Assessment: Traditional methods focus only on damage to the main structure, such as beam-column joints, and cannot quantify acceleration damage to electrical equipment or corner damage to pipelines. For functional buildings such as data centers and hospitals, this can easily lead to misjudgments of "intact structure, but functional failure." This invention constructs dedicated damage factors for each of the three types of components, achieving a unified quantitative assessment of structural, electrical, and pipeline damage.

[0039] 3. Objective and Quantifiable Weighting: Traditional methods rely entirely on engineers' experience for weighting, resulting in significant differences in evaluation results among different personnel and poor consistency. This invention establishes a calculation formula based on the entire life cycle cost (construction cost, operation and maintenance cost, and repair cost) and repair difficulty (procedures, time consumption, and replacement difficulty). The weighting coefficients are quantifiable, reproducible, and traceable, significantly reducing the subjective bias rate and ensuring that the evaluation results are in line with engineering standards.

[0040] 4. Cost Reduction and Efficiency Improvement: Traditional methods cannot distinguish between coupled damage areas and ordinary structural damage areas, and can only perform full-area detection and overall repair, resulting in a significant waste of funds and manpower. This invention uses a dual-threshold initial screening of "main reinforcement yield + concrete damage index ≥ 0.6", and then verifies weak areas through comprehensive damage factors to accurately locate the damage range, significantly reducing redundant repair costs and demonstrating strong engineering practicality.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A damage assessment method for electrical-structural coupled seismic resistance, characterized in that, Includes the following steps: S1. Based on the feedback effect of the mass, stiffness, constraint and contact of electrical equipment on the dynamic response of the main structure, establish a coupled finite element model of the reinforced concrete main structure, electrical equipment and pipelines; S2. Damage factors for reinforced concrete main structures, electrical equipment and pipelines are defined as follows: damage factors for reinforced concrete main structures, electrical equipment and pipelines are constructed based on damage index, peak acceleration at the top and relative rotation angle of pipelines, respectively. S3. Confirmation of damage weight coefficients: Specifically, under the coupled seismic system, based on the full life cycle cost and repair difficulty, the damage weight coefficients of the reinforced concrete main structure, electrical equipment and pipelines corresponding to the damage factors defined in S2 are determined respectively. The damage weighting coefficient is determined based on the total life cycle cost and the difficulty of repair; the total life cycle cost includes the initial cost, maintenance cost, and repair cost after damage; the difficulty of repair includes the repair procedures, repair time, and replacement difficulty; Repair difficulty The expression is as follows: ； in: For the fixed coefficient of repair time, To change the fixed coefficient of difficulty, For the fixed coefficient of the repair process, satisfy ; The time-consuming and difficult repair process To change the difficulty level. The difficulty level of the repair process; Damage weighting coefficient The expression is as follows: ； in, The total lifecycle cost of the main structure, electrical equipment, or pipelines. The total life-cycle cost of the main structure, For the total life cycle cost of electrical equipment, For the total life cycle cost of the pipeline, The difficulty of repairing the main structure, pipelines, or electrical equipment; S4. Division of coupled damage regions: In the coupled finite element model established in S1, input the actual earthquake action, and determine multiple coupled damage regions with potential severe damage based on the damage index of concrete and the stress of steel bars. S5. Based on the weighted summation of the damage factor defined in S2 and the corresponding weight coefficients in S3, calculate the coupled damage comprehensive factor, classify the damage level, and propose repair strategies.

2. The damage assessment method for electrical-structural coupling seismic resistance according to claim 1, characterized in that, The coupled finite element model treats electrical equipment as a multi-mass system, pipelines as beam elements based on axial and bending stiffness, simulates the anchoring effect of electrical equipment, pipelines and reinforced concrete main structure through rigid connections or spring elements, and performs seismic time history analysis simultaneously based on the coupled finite element model.

3. The damage assessment method for electrical-structural coupling seismic resistance according to claim 1, characterized in that, The damage factor of the reinforced concrete main structure is calculated based on the Park-Ang method, and the calculation formula is as follows: ； in: For the damage factors of reinforced concrete main structures, For displacement, For the ultimate displacement, This is the energy consumption weighting coefficient. To accumulate energy consumption, It represents the yield strength.

4. The damage assessment method for electrical-structural coupling seismic resistance according to claim 1, characterized in that, The damage factor of electrical equipment is calculated based on the peak acceleration at the top of the equipment, as shown in the following formula: ； in: Damage factors for electrical equipment The allowable acceleration at the top of the electrical equipment. This refers to the acceleration of the top of electrical equipment during an earthquake.

5. The damage assessment method for electrical-structural coupling seismic resistance according to claim 1, characterized in that, The pipeline damage factor is calculated based on the pipeline's relative rotation angle, as shown in the following formula: ； in: Damage factors for pipelines, For the allowable relative angle of the pipeline, The angle of the pipeline is the angle between the input pipeline and the output pipeline.

6. The damage assessment method for electrical-structural coupling seismic resistance according to claim 1, characterized in that, When identifying multiple potential coupled damage regions with severe damage, the ground motion is first input into the coupled finite element model. If the stress of the main reinforcing bars reaches the yield strength and the damage index of the concrete reaches 0.6 or above, the region is initially identified as a single potential coupled severe damage region. Then, the damage factors of electrical equipment and pipelines in the identified multiple potential coupled severe damage regions are calculated separately, and the coupled damage comprehensive factor is calculated to evaluate the weak areas in the structure.

7. The damage assessment method for electrical-structural coupling seismic resistance according to claim 6, characterized in that, Coupling damage comprehensive factor of coupled damage region The expression is as follows: ； in: For the damage factors of reinforced concrete main structures, Damage factors for electrical equipment Damage factors for pipelines, The damage weighting coefficient for the main structure. For damage weighting coefficients of electrical equipment, This is the damage weighting coefficient for the pipeline.

8. The damage assessment method for electrical-structural coupling seismic resistance according to claim 7, characterized in that, Damage severity is classified according to the following criteria: if coupled with damage composite factors If the value is less than 0.1, it is determined that no repair is needed; if 0.1 ≤ If the value is ≤0.65, it is determined that repair is needed and continued use is permitted after repair; if If the value is greater than 0.65, it is determined that the repair is impossible.

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