Method for determining welding sequence of curved steel structure roof based on Internet of Things technology

Abstract

The invention belongs to the related field of intelligent construction of civil engineering, and discloses a curved steel structure roof welding sequence determination method based on the Internet of Things, which comprises the following steps: real-time monitoring of the deviation between the temperature of a welding site and the welding temperature obtained by simulation is realized through finite element simulation software and an Internet of Things system; calculating a welding temperature deviation index through the dynamic data, and further comparing the welding temperature deviation index with the maximum threshold value of the welding temperature deviation index; when the difference between the welding temperature and the welding temperature in the simulation process is too large, the worker adjusts the welding process of the curved steel structure roof; the technology of the internet of things is fused into the welding construction process of curved steel structure roof welding, and the construction quality and the construction efficiency of curved steel structure roofs are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the field of intelligent construction and relates to a method for determining a welding sequence of a curved steel structure roof based on Internet of Things technology. Background Art

[0002] During the construction of curved steel structure roofs, ensuring the correct welding sequence is the core link to ensure structural safety; the purpose is to determine a reasonable welding sequence through reasonable planning and dynamic monitoring to ensure the quality of welding to ensure the safety and durability of the structure, improve construction efficiency, and reduce rework; at the same time, it can not only detect welding problems in a timely manner and reduce the loss of steel during welding, but also ensure the long-term stability of the structure, reduce maintenance costs, and improve the overall benefits of the project; in the face of complex and changeable construction environments, a reasonable welding sequence is a strong guarantee for structural safety and project benefits.

[0003] However, in the construction process of curved steel structure roof, determining the welding sequence is a critical and complex link. How to optimize the welding sequence while ensuring welding quality and structural safety has always been a core issue in steel structure construction; traditional methods for determining the welding sequence mostly rely on manual experience and manual calculations, which are not only prone to errors, but also difficult to adjust and optimize in real time. There is a lack of methods for determining the welding sequence in real time during the construction process. In addition, although the Internet of Things technology has begun to be initially applied in steel structure projects, there is still a lack of methods for determining the welding sequence of curved steel structure roofs based on the Internet of Things technology. Summary of the invention

[0004] The purpose of the present invention is to provide a method for determining the welding sequence of a curved steel structure roof based on the Internet of Things in view of the complicated welding process during the construction of the curved steel structure roof.

[0005] The present invention is achieved through the following technical solutions:

[0006] According to the curved steel structure roof part to be welded, a three-dimensional finite element model of the welding specimen is established.

[0007] The welding residual stress generated by different welding sequences is simulated in the finite element software, the welding sequence with the smallest welding residual stress is screened out, and the welding sensitive area is found.

[0008] Temperature sensors are arranged in welding-sensitive areas at the welding site and connected to the Internet of Things system.

[0009] Enter the calculation formula of welding temperature deviation index ω into the IoT system:

[0010]

[0011] (1) Where: ω is the welding temperature deviation index; n is the number of measurement data; Δt is the time difference between two measurements; t i-1 is the starting time of the two measurements; t i is the time end point of two measurements; T r,i (t) is the real-time temperature measured at the ith time; T s (t) is the temperature calculated during the simulation process;

[0012] Setting a maximum threshold value ω of welding deviation index in the IoT system max :

[0013]

[0014] (2) Where: ω max is the maximum threshold of welding deviation; k1 and k2 are constants related to welding materials and welding processes; k3 is a coefficient related to structural curvature, which can be obtained through numerical simulation according to the specific structural type; T max is the maximum temperature during welding; T a is the welding environment temperature; L is the length of the welding path; R is the curvature radius of the curved steel structure roof;

[0015] When the welding temperature deviation index ω is greater than the maximum welding deviation threshold ω max When adjusting the welding process of the curved steel structure roof.

[0016] The beneficial effects of the present invention are as follows: in view of the difficulty in determining the welding sequence during the construction of a curved steel structure roof, the present invention proposes a welding sequence determination method that can be adjusted in real time during the construction process; the method combines the welding sequence of the curved steel structure roof with the Internet of Things technology, and provides a method for real-time monitoring of the welding temperature changes of the curved steel structure roof; this method can not only monitor the welding temperature to ensure the safety and durability of the welded structure, but also reduce the loss of steel during the welding process, reduce maintenance costs, and improve the overall benefits of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and by way of embodiments.

[0019] Example

[0020] A method for determining the welding sequence of a curved steel structure roof based on the Internet of Things technology is characterized in that, for a curved steel structure roof, the welding path length is 5m, the curvature radius of the curved steel structure is 20m, the maximum temperature of the welding area is 1500℃, the welding ambient temperature is 25℃, and the temperature sensor at the welding site records the temperature every 5 seconds, for a total of 10 measurements. The following is the real-time temperature data measured by the temperature sensor: T r,1 (t1) = 1480°C, T r,2 (t2) = 1490°C, T r,3 (t3) = 1500°C, T r,4 (t4) = 1485°C, T r,5 (t5) = 1475°C, T r,6 (t6) = 1490 °C, T r,7 (t7) = 1500°C, T r,8 (t8) = 1482°C, T r,9 (t9) = 1480°C, T r,10 (t 10 )=1495℃;Calculation constants: k1=0.1,k2=0.5,k3=0.02;

[0021] A steel structure engineering cost management method based on the Internet of Things comprises the following steps:

[0022] Step 1: Establish a three-dimensional finite element model of the welding specimen based on the curved steel structure roof part to be welded.

[0023] Step 2: Simulate the welding residual stress generated by different welding sequences in the finite element software, select the welding sequence with the smallest welding residual stress, and find the welding sensitive area.

[0024] Step 3: Arrange temperature sensors in the welding sensitive areas of the welding site and connect them to the Internet of Things system.

[0025] Step 4: Input the calculation formula of welding temperature deviation index ω into the IoT system:

[0026]

[0027] Step 5: Set a maximum threshold value of welding deviation index ω in the IoT system max :

[0028]

[0029] Step 6: ω=12.3<ω max =32.36, welding can continue without adjusting the welding process.

[0030] Although the specific calculation method of the present invention is described above in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that various modifications or variations that can be made by technical personnel in the field without creative work on the basis of the design of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for determining the welding sequence of a curved steel structure roof based on Internet of Things technology, characterized in that: include: The first step is to establish a three-dimensional finite element model of the welding specimen according to the curved steel structure roof part to be welded; The second step is to simulate the welding residual stress generated by different welding sequences in the finite element software, select the welding sequence with the smallest welding residual stress, and find the welding sensitive area; The third step is to place temperature sensors in the welding sensitive areas of the welding site and connect them to the Internet of Things system; The fourth step is to input the calculation formula of welding temperature deviation index ω into the IoT system: (1) Where: ω is the welding temperature deviation index; n is the number of measurement data; Δt is the time difference between two measurements; t i-1 is the starting time of the two measurements; t i is the time endpoint of two measurements; T r,i (t) is the real-time temperature measured at the ith time; T s (t) is the temperature calculated during the simulation process; Step 5: Set a maximum threshold value of welding deviation index ω in the IoT system max : (2) Where: ω max is the maximum threshold of welding deviation; k1 and k2 are constants related to welding materials and welding processes; k3 is a coefficient related to structural curvature, which can be obtained through numerical simulation according to the specific structural type; T max is the maximum temperature during welding; T a is the welding environment temperature; L is the length of the welding path; R is the curvature radius of the curved steel structure roof; Step 6: When the welding temperature deviation index ω is greater than the maximum welding deviation threshold ω max When adjusting the welding process of the curved steel structure roof.

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