Double-angle-steel roof truss safety evaluation method and system and storage medium

Abstract

The embodiment of the invention provides a safety evaluation method and system for a double-angle steel roof truss and a storage medium, and the safety evaluation method comprises the steps: comparing a comprehensive corrosion damage parameter and a corrosion rate limit value of a to-be-evaluated steel member, and when the comprehensive corrosion damage parameter is smaller than the corrosion rate limit value, judging whether the to-be-evaluated steel member is the corrosion rate limit value; if yes, calculating the equivalent tensile bearing capacity after corrosion according to the steel strength reduction coefficient and the comprehensive corrosion damage parameter; the actual internal force borne by the steel member to be evaluated is calculated, and the resistance response-effect ratio is obtained based on the actual internal force and the equivalent tensile bearing capacity after corrosion; and obtaining a safety evaluation result based on the resistance response-effect ratio. According to the safety evaluation method provided by the invention, the safety grade of each steel member of the double-angle steel roof truss can be conveniently and accurately judged, data support is provided for whether the steel roof truss needs to be reinforced or replaced subsequently or not, and the reliability and economical efficiency of operation and maintenance of an industrial factory building are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of safety evaluation of double-angle steel roof trusses, and in particular to a safety evaluation method, system and storage medium for double-angle steel roof trusses. Background Art

[0002] Common roof trusses in single-story industrial plants include triangular and trapezoidal steel trusses, most often constructed with double-angle steel members. These trusses offer a wide span, low weight, and thin plate thickness. These characteristics lead to rapid corrosion of double-angle steel trusses in industrial atmospheres containing high levels of corrosive dust and water vapor. Roof collapses are common, resulting in significant economic losses and casualties. For existing industrial plants in urgent need of maintenance, the ability to quickly and easily assess the safety of double-angle steel trusses and promptly implement appropriate repair measures can prevent potential dangers from occurring, maintaining the stability of the entire building structure and preventing serious accidents such as roof collapse.

[0003] A commonly used safety assessment method for corroded steel structures is to evaluate their load-bearing capacity and structural characteristics. This load-bearing capacity-based safety assessment primarily considers the impact of corrosion on the cross-section of the steel structure and the material strength of the steel structure. However, when calculating the reduction in material strength due to corrosion, existing methods multiply the steel strength by a reduction factor of 0.8 if the corrosion damage exceeds 10% of the initial thickness or the remaining thickness is no greater than 5 mm. This means that the strength of corroded steel relies solely on a single criterion and a fixed reduction factor. Because corrosion is non-uniform, this calculation method lacks specificity in considering the reduction in steel strength due to corrosion. It fails to comprehensively account for the varying amounts of corrosion damage inflicted on various parts of the steel, and therefore cannot derive a corresponding steel strength reduction factor based on the varying amounts of corrosion damage. Consequently, using existing methods to calculate the material strength of steel structures due to corrosion can lead to inaccurate assessments of the safety of steel roof trusses. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a double-angle steel roof truss safety evaluation method, system and storage medium, which are used to solve the technical problems existing in the above-mentioned background technology.

[0005] To achieve the above-mentioned objectives, a first aspect of an embodiment of the present invention provides a safety evaluation method for a double-angle steel roof truss, the safety evaluation method comprising: obtaining various thicknesses of a steel member to be evaluated of the steel roof truss, and calculating a comprehensive corrosion damage parameter of the steel member to be evaluated based on the various thicknesses, wherein the various thicknesses include an uncorroded thickness, a remaining average thickness after corrosion, and a remaining maximum thickness after corrosion; calculating a corrosion rate limit based on the comprehensive corrosion damage parameter, and determining whether the comprehensive corrosion damage parameter is less than the corrosion rate limit; if so, performing the following operations: calculating an equivalent tensile bearing capacity after corrosion based on a steel strength reduction factor and the comprehensive corrosion damage parameter; calculating the actual internal force borne by the steel member to be evaluated based on its position in the steel roof truss and the actual load value it bears, and obtaining a stress-resistance ratio based on the actual internal force and the equivalent tensile bearing capacity after corrosion; and obtaining a safety evaluation result based on the stress-resistance ratio, wherein the steel strength reduction factor is calculated based on the tensile strength of the steel of the steel roof truss and the comprehensive corrosion damage parameter of the steel.

[0006] Optionally, if it is determined that the comprehensive corrosion damage parameter is not less than the corrosion rate limit, the safety evaluation result of the steel component to be evaluated is grade D.

[0007] Optionally, the calculation process of the comprehensive corrosion damage parameter includes: calculating the total corrosion rate based on the remaining average thickness after corrosion and the uncorroded thickness; calculating the non-uniform corrosion rate based on the remaining maximum thickness after corrosion, the remaining average thickness after corrosion, and the uncorroded thickness; and obtaining the comprehensive corrosion damage parameter based on the total corrosion rate and the non-uniform corrosion rate.

[0008] Optionally, the total corrosion rate, non-uniform corrosion rate, and comprehensive corrosion damage parameter are obtained based on the following formulas:

[0009]

[0010]

[0011] in, D w is the comprehensive corrosion damage parameter, is the total corrosion rate, is the non-uniform corrosion rate, is the uncorroded thickness, is the remaining average thickness after corrosion, is the maximum remaining thickness after corrosion.

[0012] Optionally, the tensile strength of the steel of the steel roof truss is determined based on a tensile test, and the tensile strength of the steel and the comprehensive corrosion damage parameters of the steel are fitted using the least squares method to calculate the steel strength reduction factor.

[0013] Optionally, the corrosion rate limit is calculated based on the comprehensive corrosion damage parameter, and the calculation formula is:

[0014] in, is the corrosion rate limit of the steel structure to be evaluated, D w is the comprehensive corrosion damage parameter of the steel component to be evaluated, is the cross-sectional width of the steel member to be evaluated.

[0015] Optionally, the equivalent tensile bearing capacity after corrosion is calculated based on the steel strength reduction coefficient and the comprehensive corrosion damage parameter, and the calculation formula is:

[0016] in, is the equivalent tensile bearing capacity after corrosion, is the equivalent tensile strength of the steel member to be evaluated after corrosion, is the uncorroded thickness of the steel member to be evaluated, D w is the comprehensive corrosion damage parameter of the steel component, is the cross-sectional width of the steel member to be evaluated; The equivalent tensile strength of the steel member to be evaluated after corrosion is calculated based on the steel strength reduction factor and the original design tensile strength of the steel member to be evaluated. The calculation formula is:

[0017] in, is the steel strength reduction factor, is the original design tensile strength of the steel member to be evaluated.

[0018] Optionally, the resistance stress ratio is obtained based on the actual internal force and the equivalent tensile bearing capacity after corrosion, and the calculation formula is:

[0019] in, is the resistance effect ratio, is the equivalent tensile bearing capacity after corrosion, is the actual internal force.

[0020] In a second aspect, an embodiment of the present invention provides a double-angle steel roof truss safety evaluation system, the safety evaluation system comprising: a memory; and a processor, the processor being configured to execute a safety evaluation method according to any one of the claims of the present application.

[0021] In a third aspect, the present invention provides a machine-readable storage medium having stored thereon instructions for enabling a machine to execute any of the above-mentioned security evaluation methods of the present application.

[0022] Through the above technical solution, the embodiment of the present invention derives a comprehensive corrosion damage parameter based on the thickness of the corroded steel member to be evaluated. This comprehensive corrosion damage parameter can comprehensively consider the different degrees of damage caused by corrosion to the steel member. The corrosion rate limit of the steel member to be evaluated is then calculated based on the comprehensive corrosion damage parameter, and the safety evaluation result of the steel member to be evaluated is determined by determining the relationship between the comprehensive corrosion damage parameter and the corrosion rate limit. When the comprehensive corrosion damage parameter is less than the corrosion rate limit, the equivalent tensile bearing capacity of the corroded steel member is calculated in combination with the steel strength reduction factor. Because the steel strength reduction factor in the present invention comprehensively considers the impact of steel on tensile strength at different corrosion damage stages, the calculated equivalent tensile bearing capacity is more accurate. Furthermore, since different steel members are located in different positions within the steel roof truss and thus bear different loads, the actual internal forces borne by the steel member to be evaluated are calculated in combination with the position of the steel member to be evaluated within the steel roof truss and the actual load value it bears. The safety evaluation result is obtained by combining the actual internal force and the equivalent tensile bearing capacity with the calculated resistance-effect ratio, so as to more accurately judge the safety level of each steel component of the double-angle steel roof truss in the industrial atmospheric environment. It also provides data support for whether the steel roof truss needs to be reinforced or replaced in the future, thereby improving the reliability and economy of industrial plant operation and maintenance.

[0023] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings: Figure 1 The present invention provides a schematic flow chart of a double-angle steel roof truss safety evaluation method. DETAILED DESCRIPTION

[0025] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0026] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of laws and regulations. In the embodiments of this application, certain software, components, models, and other existing solutions in the industry may be mentioned. These should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of this application, but it does not mean that the applicant has or will necessarily use such solutions.

[0027] Figure 1 This is a schematic flow chart of a double-angle steel roof truss safety evaluation method provided by an embodiment of the present invention. Figure 1 As shown, the safety evaluation method includes steps S1 to S4.

[0028] Step S1: Obtaining various thicknesses of the steel members to be evaluated of the steel roof truss, calculating the comprehensive corrosion damage parameters of the steel members to be evaluated based on the various thicknesses, and calculating the corrosion rate limit based on the comprehensive corrosion damage parameters; Step S2: Determine whether the comprehensive corrosion damage parameter is less than the corrosion rate limit. If so, proceed to step S3; if not, proceed to step S7; Step S3: Calculate the equivalent tensile bearing capacity after corrosion based on the steel strength reduction factor and the comprehensive corrosion damage parameter; Step S4: Calculating the actual internal force borne by the steel member to be evaluated based on its position in the steel roof truss and the load value it actually bears; Step S5: Obtaining the stress-resistance ratio based on the actual internal force and the equivalent tensile bearing capacity after corrosion; Step S6: Based on the resistance-effect ratio, a safety evaluation result is obtained; Step S7: The safety evaluation result of the steel component to be evaluated is obtained as level D.

[0029] The various thicknesses include the uncorroded thickness, the average remaining thickness after corrosion, and the maximum remaining thickness after corrosion. The steel strength reduction factor is calculated based on the tensile strength of the steel used in the steel roof truss and the comprehensive corrosion damage parameter of the steel. The comprehensive corrosion damage parameter of the steel is calculated based on the uncorroded thickness, the average remaining thickness after corrosion, and the maximum remaining thickness after corrosion.

[0030] Regarding step S1, in some embodiments, the comprehensive corrosion damage parameter D w The calculation process includes steps S101 to S103.

[0031] Step S101: According to the remaining average thickness after corrosion and uncorroded thickness , calculate the total corrosion rate , and its calculation formula is:

[0032] Step S102: According to the maximum remaining thickness after corrosion , the remaining average thickness after the corrosion and the uncorroded thickness Calculate the non-uniform corrosion rate , and its calculation formula is:

[0033] Step S103: According to the total corrosion rate and the non-uniform corrosion rate , and obtain the comprehensive corrosion damage parameter D w , and its calculation formula is:

[0034] Since corrosion often does not occur evenly in all parts of steel components, for example, stress concentration areas and parts that are more frequently in contact with corrosive media are more susceptible to corrosion. If only the thickness of the steel component before and after corrosion is measured, and the corrosion rate is calculated based on the thickness change before and after corrosion, the different degrees of corrosion in different parts are ignored, resulting in a one-sided evaluation. Therefore, in the present invention, the total corrosion rate is used to reflect the average reduction in the overall thickness of the corroded steel component, reflecting the comprehensive impact of corrosion on the component size, while the non-uniform corrosion rate focuses on the different degrees of corrosion caused by corrosion on different parts of the component. The comprehensive corrosion damage parameter obtained by combining the total corrosion rate and the non-uniform corrosion rate can more comprehensively measure the actual damage caused by corrosion to steel components, avoiding the one-sided evaluation caused by considering only a single factor.

[0035] It is understandable that the safety performance of steel components, such as load-bearing capacity and stability, is closely related to their cross-sectional dimensions, and corrosion will reduce their cross-sectional area, thereby reducing their load-bearing capacity. In some embodiments, the corrosion rate limit is calculated based on the comprehensive corrosion damage parameter of the steel component to be evaluated and the cross-sectional width of the steel component to be evaluated, and the calculation formula is:

[0036] in, is the corrosion rate limit of the steel structure to be evaluated, D wis the comprehensive corrosion damage parameter of the steel component to be evaluated, is the cross-sectional width of the steel member to be evaluated measured using a vernier caliper.

[0037] The corrosion rate limit can clearly indicate the severity of corrosion on steel components, providing a quantitative basis for measuring the safety of steel components. The embodiments of the present invention use a comprehensive relationship between corrosion damage parameters and corrosion rate limits to determine whether a steel component can safely withstand the design load.

[0038] Specifically, when the comprehensive corrosion damage parameter of the steel structure under evaluation is determined to be less than the corrosion rate limit, the equivalent tensile bearing capacity after corrosion is calculated based on the steel strength reduction factor and the comprehensive corrosion damage parameter. It is understandable that due to corrosion, the tensile strength of the steel will also decrease to varying degrees. Therefore, it is inaccurate to evaluate the performance of the corroded steel solely based on the strength before corrosion or the strength calculated using a fixed strength reduction factor.

[0039] Therefore, in an embodiment of the present invention, the tensile strength of the steel of the steel roof truss is determined based on a tensile test, and the tensile strength of the steel and the comprehensive corrosion damage parameter of the steel are fitted using the least squares method to calculate the steel strength reduction factor.

[0040] Specifically, for the corroded area of ​​the double-angle steel truss, the steel member bearing the least stress was identified based on the force diagram of the steel truss provided in the original design drawings. A portion of the corroded steel plate from this member was then cut and processed into 10 test pieces, and the thickness of each test piece was measured. In this example, the processed test pieces were rectangular steel plates measuring 40 mm in length and 20 mm in width. The 40 mm and 20 mm values ​​are provided for illustrative purposes only and are not intended to limit the steel plate size.

[0041] Before measurement, each specimen was simply ground and rust-removed using an angle grinder. During measurement, an ultrasonic thickness gauge was used to measure the cross-sectional thickness of each specimen 5 times, and the average of the measured thickness results was taken to obtain the remaining average thickness of the specimen after corrosion. , take the maximum value of the measured thickness results to obtain the maximum remaining thickness of the specimen after corrosion , according to the thickness design value of the steel component in the original design drawing, the original design thickness of the specimen is obtained .

[0042] Then, the comprehensive corrosion damage parameters of each specimen were calculated based on the thickness measurement results of each specimen. Finally, a monotonic tensile test was performed on all specimens using a hydraulic universal testing machine to obtain the tensile strength of each specimen, and the tensile strength and comprehensive corrosion damage parameters of each specimen were calculated using the least squares method. D wFitting is performed to obtain the steel strength reduction factor of the double angle steel roof truss of the industrial plant , and its calculation formula is:

[0043] Since the corrosion of steel components is often not evenly distributed throughout the entire structure, there may be cases where local corrosion is more severe. By cutting off the steel plates in the corroded area for testing, the strength reduction of the steel in that area due to corrosion can be obtained more directly and accurately. If the steel strength reduction coefficient of the steel component to be evaluated is calculated directly, it may be necessary to make an average estimate of the corrosion situation of the entire component. This is prone to errors due to the large differences in the degree of corrosion in different parts of the component. The reduction coefficient calculated by cutting off the steel plates in the corroded area can avoid masking the impact of local severe corrosion on the bearing capacity of the component due to the overall average estimate. In addition, the steel strength reduction coefficient obtained by fitting the tensile strength and comprehensive corrosion damage parameters of the steel integrates both the total corrosion rate and the non-uniform corrosion rate, more comprehensively reflecting the weakening effect of corrosion on the performance of the steel, avoiding the one-sidedness brought about by the single parameter evaluation, and making the strength reduction coefficient more accurately reflect the degree of corrosion damage.

[0044] Therefore, the equivalent tensile strength of the steel member to be evaluated after corrosion is , according to the steel strength reduction factor and the original design tensile strength of the steel member The calculation formula is:

[0045] The equivalent tensile bearing capacity after corrosion is calculated based on the steel strength reduction factor and the comprehensive corrosion damage parameter. The calculation formula is:

[0046] in, is the equivalent tensile bearing capacity after corrosion, is the equivalent tensile strength of the steel member to be evaluated after corrosion, is the uncorroded thickness of the steel member to be evaluated, D w is the comprehensive corrosion damage parameter of the steel component, is the cross-sectional width of the steel member.

[0047] Because the steel members to be evaluated are located in different positions within the steel truss, the loads they bear are also different. Therefore, according to the original design drawings of the steel truss, a calculation model of the steel truss was established using the 2D Steel Structure Design module in PKPM software. Parameters such as the dead load, live load, and wind load borne by the steel truss were input into the calculation model based on the actual project conditions to determine the actual internal forces borne by the corresponding steel members.

[0048] Finally, based on the actual internal force and the equivalent tensile bearing capacity after corrosion, the resistance stress ratio is obtained, and its calculation formula is:

[0049] in, is the resistance effect ratio, is the equivalent tensile bearing capacity after corrosion, After PKPM modeling and calculation, the actual internal forces borne by the corresponding steel components are obtained.

[0050] Based on the calculated stress-resistance ratio, the safety evaluation result is obtained. Specifically, when R≥1.0, the safety evaluation of the steel component is a level; when 1.0>R≥0.95, the safety evaluation of the steel component is b level; when 0.95>R≥0.88, the safety evaluation of the steel component is c level; when R<0.88, the safety evaluation of the steel component is d level. It should be noted that among the levels divided here, level a represents the highest safety of the steel component at this time, and level d represents the lowest safety. Moreover, the division of safety rating levels here is only exemplary, and those skilled in the art can adjust the levels and specific numerical ranges according to different actual applications.

[0051] When it is judged that the comprehensive corrosion damage parameter of the steel structure to be evaluated is not less than the corrosion rate limit, this indicates that the corrosion of the steel structure is relatively serious at this time, and it may no longer be able to safely bear the design load. There are certain safety hazards and it needs to be repaired. Therefore, the safety evaluation result is directly obtained as the preset d level. In summary, the double-angle steel roof truss safety evaluation method provided by the embodiment of the present invention calculates the comprehensive corrosion damage parameter according to the thickness of the steel structure to be evaluated. This parameter comprehensively considers the total corrosion rate and the non-uniform corrosion rate, and more comprehensively reflects the weakening effect of corrosion on the performance of the steel structure. Moreover, by calculating the corrosion rate limit in combination with the comprehensive corrosion damage parameter, it is possible to more accurately judge whether the steel structure can safely bear the design load in combination with the corrosion situation, thereby obtaining its safety evaluation result, determining which steel structures need to be repaired and the urgency of the repair, and helping to reasonably allocate maintenance resources and improve the efficiency and economy of maintenance.

[0052] In a second aspect, an embodiment of the present invention provides a double-angle steel roof truss safety evaluation system, the safety evaluation system comprising: a memory; and a processor, the processor being configured to execute the safety evaluation method according to any one of the claims.

[0053] In a third aspect, an embodiment of the present invention provides a machine-readable storage medium having stored thereon instructions for enabling a machine to execute any of the above-mentioned security evaluation methods of the present application.

[0054] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0055] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0056] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0057] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0058] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0059] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0060] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can be implemented using any method or technology for information storage. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change RAM (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0061] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0062] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A double-angle steel roof truss safety evaluation method, characterized in that: The safety evaluation method includes: Obtaining various thicknesses of the steel member to be evaluated of the steel roof truss, and calculating the comprehensive corrosion damage parameter of the steel member to be evaluated based on the various thicknesses, wherein the various thicknesses include the uncorroded thickness, the average remaining thickness after corrosion, and the maximum remaining thickness after corrosion; Calculate the corrosion rate limit value based on the comprehensive corrosion damage parameter, and determine whether the comprehensive corrosion damage parameter is less than the corrosion rate limit value. If so, perform the following operations: Calculating the equivalent tensile bearing capacity after corrosion based on the steel strength reduction factor and the comprehensive corrosion damage parameter; Calculating the actual internal force borne by the steel member to be evaluated according to the position of the steel member to be evaluated in the steel roof truss and the load value actually borne by the steel member, and obtaining the stress-resistance ratio based on the actual internal force and the equivalent tensile bearing capacity after corrosion; and Based on the resistance-effect ratio, the safety evaluation result is obtained. The steel strength reduction coefficient is calculated based on the tensile strength of the steel of the steel roof truss and the comprehensive corrosion damage parameter of the steel.

2. The safety evaluation method according to claim 1, characterized in that: If it is determined that the comprehensive corrosion damage parameter is not less than the corrosion rate limit, the safety evaluation result of the steel component to be evaluated is grade D.

3. The safety evaluation method according to claim 1, characterized in that: The calculation process of the comprehensive corrosion damage parameters includes: The total corrosion rate is calculated based on the remaining average thickness after corrosion and the uncorroded thickness; Calculating a non-uniform corrosion rate based on the maximum thickness remaining after corrosion, the average thickness remaining after corrosion, and the uncorroded thickness; and The comprehensive corrosion damage parameter is obtained according to the total corrosion rate and the non-uniform corrosion rate.

4. The safety evaluation method according to claim 3, characterized in that: The total corrosion rate, non-uniform corrosion rate and comprehensive corrosion damage parameter are obtained based on the following formulas: in, D w is the comprehensive corrosion damage parameter, is the total corrosion rate, is the non-uniform corrosion rate, is the uncorroded thickness, is the average remaining thickness after corrosion, is the maximum remaining thickness after corrosion.

5. The safety evaluation method according to claim 1, characterized in that: The tensile strength of the steel of the steel roof truss is determined based on a tensile test, and the tensile strength of the steel and the comprehensive corrosion damage parameter of the steel are fitted using the least squares method to calculate the steel strength reduction factor.

6. The safety evaluation method according to claim 1, characterized in that: The corrosion rate limit is calculated based on the comprehensive corrosion damage parameter, and the calculation formula is: in, is the corrosion rate limit of the steel structure to be evaluated, D w is the comprehensive corrosion damage parameter of the steel component to be evaluated, is the cross-sectional width of the steel member to be evaluated.

7. The safety evaluation method according to claim 1, characterized in that: The equivalent tensile bearing capacity after corrosion is calculated based on the steel strength reduction coefficient and the comprehensive corrosion damage parameter, and the calculation formula is: in, is the equivalent tensile bearing capacity after corrosion, is the equivalent tensile strength of the steel member to be evaluated after corrosion, is the uncorroded thickness of the steel member to be evaluated, D w is the comprehensive corrosion damage parameter of the steel component, is the cross-sectional width of the steel member to be evaluated; The equivalent tensile strength of the steel member to be evaluated after corrosion is calculated based on the steel strength reduction factor and the original design tensile strength of the steel member to be evaluated. The calculation formula is: in, is the steel strength reduction factor, is the original design tensile strength of the steel member to be evaluated.

8. The safety evaluation method according to claim 1, wherein: The resistance stress ratio is obtained based on the actual internal force and the equivalent tensile bearing capacity after corrosion, and its calculation formula is: in, is the resistance effect ratio, is the equivalent tensile bearing capacity after corrosion, is the actual internal force.

9. A double angle steel roof truss safety evaluation system, characterized in that: The safety evaluation system includes: Memory; and A processor, wherein the processor is configured to execute the security evaluation method according to any one of claims 1 to 8.

10. A machine-readable storage medium having stored thereon instructions for causing a machine to execute any of the above-mentioned security evaluation methods of the present application.

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