Crane stress monitoring system: Early warning and breakage prevention

1. Product Introduction

This thing is a "CT machine" installed on the metal structure of cranes, specifically for treating internal injuries that are invisible to the naked eye. The traditional method relies on manual hammering and tapping? The crack can only be discovered when it grows to 5mm. The accident has already planted a landmine! Now, this system directly welds sensors onto the main beams and legs, providing full coverage like a fabric neural network, and closely monitors the development of stress, deformation and cracks in real time. For instance, in the case of the gantry crane at Ningbo Port, the system detected a 0.1mm hidden crack in the weld of the main beam and issued a warning for major overhaul three months in advance, effectively nipping in the bud a 30-ton molten steel overturning accident. What's even more powerful is that it doesn't consume electricity 24 hours a day - it only starts monitoring during high-risk periods such as overload and strong winds, reducing energy consumption by 701T to 3T, which is more energy-efficient than traditional continuous monitoring, like an "intelligent switch".

2. Technical principles

The core lies inThree-level defense network​：

​Level 1: Finite element analysis to locate risk pointsFirst, use software to simulate various extreme working conditions of the crane, lock down the stress concentration areas (such as the mid-span of the main beam and the welds of the door legs), and precisely install sensors like conducting a "pre-health check" for the equipment.

​Level 2: Vibrating wire strain gauge captures microscopic deformationThe sensor is welded onto the steel beam. As soon as the crane is subjected to force, the frequency of the strain gauge immediately drifts, and even 0.1 micro-strain (equivalent to the weight of a fingernail pressing on 1 gram) cannot escape. The anti-interference ability is even more astonishing: Radiation from 1600℃ molten steel in steel mills? Just carry on as usual! The error was reduced to within 2%, while the error of the resistance strain gauge had already soared to 15% at high temperatures.

​Level 3: Intelligent Decision-making Based on Random Forest AlgorithmThe system feeds data such as lifting capacity, wind speed and rotation Angle to the AI model, and triggers stress monitoring within 0.2 seconds at the moment of overload. For instance, when the lifting capacity is ≥90% rated value or the wind speed is greater than 10m/s, the "CT scanning mode" is immediately activated, and it is usually dormant to save power.

3. Scope of application

​Metallurgical high-risk areaThe most recognized one: In the steelmaking workshop, the crane lifts the steel ladle, and the sensor is coated with ceramic to withstand a temperature of 800℃, with real-time monitoring of the deflection of the main beam. Wuhan Iron and Steel Corporation's actual measurement proved that when the load was overloaded by 5%, the mid-span deflection exceeded the limit by 12mm, and the system immediately cut off the lifting power supply.

​Port machineryEssential demand: 40-ton gantry crane at Qingdao Port, fiber optic cable tie rod welding, salt spray corrosion caused by sea wind? The fluorinated acrylate coating has withstood the test, with zero false alarms for three years. When unloading containers, the AI automatically locks the swing trajectory of the hook, saving the driver the action of the 70% stretching its neck to look at the blind spot.

​Bridge constructionLife-saving use: During the beam erection of the Shanghai-Suzhou-Nantong Yangtze River Bridge, the system was embedded in the pin shaft hole to warn of insufficient pre-tightening of the bolts in the 600-ton beam section, preventing the tragedy of overturning.

4. Product display

All the hardware is military-grade "tough nuts to crack"

• ​SensorStainless steel encapsulated vibrating wire strain gauge, with a diameter of 3mm, directly welded to the steel beam, and IP68 protection that even high-pressure water guns cannot damage.
• ​Main cabinetThe explosion-proof box is stuffed with an industrial control computer and a fiber optic demodulator. Even when the outer shell is 8 meters away from the steel water tank, it can still run stably at 72℃. It also features an automatic cleaning black technology - in a dusty environment, the lens is washed with water every 4 hours, which is twice as efficient as manual wiping.
• ​Software interfaceThe 3D stress cloud map is generated by dragging on the Web end. The red area represents the high-risk point. Click two points to lower the three-year stress curve - Baotou Steel workers check data like swiping through a mobile phone screen.

5. Product advantages

Saving money and life is the real skill

• ​Change the maintenance modeA certain aluminum factory has calculated that the annual loss of production capacity is 9 million yuan. Traditionally, it undergoes a three-day inspection every two years. After installing the system, it became "repair only when it breaks down", saving 4.7 million yuan in downtime costs annually.
• ​Longevity magic weaponThe 10-year-old crane in the Sany Heavy Industry workshop was reinforced at the stress concentration points under the guidance of the system, extending its scrapping period from 15 years to 21 years and saving 2.8 million yuan in the cost of replacing the entire machine.
• ​Cut energy consumption by halfAt a certain port, monitoring is only initiated when there is overload or strong wind. The actual annual electricity cost savings amount to 120,000 yuan, which is 731T lower than the power consumption of traditional continuous monitoring.

6. Typical applications

​Zhoushan Port unloaderThe system has set up 86 measurement points. Before a strong typhoon, workers rushed to repair it, and the stress of the hook suddenly soared to 189MPa (the safety threshold is 120MPa). The AI triggered sound and light alarm in seconds and automatically locked the hook to rescue the person from the falling steel coil.

​Baosteel 450-ton casting craneDuring the hoisting of the steel ladle, the main beam suddenly sank by 9mm (the national standard limit is 8mm), triggering a level two alarm and causing the system to shut down. Disassembly and inspection revealed internal rust on the load-bearing beam, with a cross-sectional loss of 221T to 3T. If it had been 10 minutes later, the beam would have broken.

​Wusong Expressway bridge erection machineWhen prefabricated beams are hoisted, AI locks the 3mm² spalling of the raceway of the slewing bearing through stress fluctuations, giving a warning six weeks earlier than traditional detection. The maintenance cost has been reduced from 500,000 to 80,000.

​7. Conclusion​

From "repair when broken" to "know before it breaks", the stress monitoring system is taking crane safety to a new dimension. A certain central state-owned enterprise has piloted the integration of digital twins - real-time data-driven virtual cranes, which can simulate the fracture critical point of an overloaded 20% with just a click of the mouse. In the era of Industry 4.0, a one-hour early warning means saving eight lives and incurring losses of tens of millions.