Shenzhen Bestning Technology Co., Ltd. specializes in the research, development, production and sales of linear displacement sensors, pull-wire linear displacement sensors, grating electronic rulers and digital displays, LVDT displacement sensors, and internal and external current modules. It is widely used in injection molding machinery, die-casting machines, bottle blowing machines, prestressing, hydraulic equipment, railway guide rail monitoring, spraying equipment, medical machinery, petrochemical exploration, measurement systems and other fields, and has won unanimous recognition from customers in terms of reliability, stability, accuracy and environmental adaptability.

The following is an introduction to the application of prestressing:

Prestressing concept Prestressing is the abbreviation of prestressing. Before the structure is subjected to external loads, stress is applied to the area under the external load in advance to improve the performance of the structure. Prestressing can be used to resist the tensile stress or bending moment borne by the structure, and pre-tensioning can be used to resist the compressive stress borne by the structure. Being good at using prestressing principles and techniques, it is possible to obtain the effect of improving structural performance and increasing the bearing capacity of the structure. Concept of prestressing: Prestressing is to add tension to the component in advance, so that the prestressed tensioned component bears tensile stress, and then causes a certain deformation to cope with the load on the steel structure itself.Schematic diagram of the test principle (omitted)

The role of prestressing: Before the engineering structure component bears the external load, prestress is applied to the steel strands in the tension module to improve the bending resistance and rigidity of the component, delay the time of cracks, and increase the durability of the component. For mechanical structures, it means to generate stress in advance, which has the advantage of improving the rigidity of the structure itself, reducing vibration and elastic deformation, and significantly improving the elastic strength of the tension module, making the original resistance stronger. Due to the shortcomings of traditional prestressing construction operations such as large tension control error, large measurement error, unmeasurable retraction value, low synchronization rate at both ends, inability to achieve dual control of tension and, lack of reliable process control means and effective detection and evaluation methods, it has gradually been replaced by intelligent and CNC tensioning technology. Modern prestressed program-controlled (intelligent, numerically controlled) tensioning technology refers to the use of automated measurement and control technology based on computer intelligence and sensor technology to achieve automated control of tensioning operations. Modern program-controlled tensioning systems consist of program-controlled hosts and operating front-ends. The operating front-end includes measurement and control circuits, oil pumps, jacks, sensors and other components.

Working principle of prestressed tensioning program-controlled system: The system host consists of an industrial tablet computer and a dedicated software system. The host wirelessly remotely controls one or more measurement and control front-ends according to preset tensioning parameters. The front end controls the oil pump motor through variable frequency output stepless speed regulation according to the host's instructions, and monitors the working pressure of the jack and the elongation value of the steel strand and feeds it back to the host. The host calculates the next instruction based on the feedback data and continues to remotely control the front end, thus forming a closed-loop control. The prestressed tensioning program-controlled system uses tensioning force as the main control indicator and elongation as the auxiliary control indicator, truly realizing the dual control of tensioning force and elongation value, ensuring that the tensioning force and elongation at both ends of the tensioning process are highly synchronized. The synchronization error is strictly controlled within the range specified in the 2011 version of the "Technical Specifications for Highway Bridge and Culvert Construction". During the test of prestressing force, the instrument can control the release pressure precisely by controlling the return oil volume, and realize controllable pressure and release rate during the release process. The retraction value of the clip and the elastic deformation of part of the steel strand in the jack cavity are measured by accurately releasing the tension to the initial stress, so as to obtain the effective elongation value of the steel strand after release. The tensioning program control system does not modify the jack. The measurement system is realized by an external ultrasonic measurement sensor, which can directly measure the length change value of the steel strand. Through real-time high-frequency monitoring of the elongation value and pressure value, the steel strand value under different tension forces can be reflected in real time on the tension-curve, and the retraction value can be directly measured.