Compression stress relaxation characteristics and failure mechanism of silicone rubber for high voltage cable accessories

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability Pub Date : 2024-11-19 DOI:10.1016/j.polymdegradstab.2024.111098

YanHui Wei , Hao Guo , XiaoLong Chen , XueJing Li , GuoChang Li , Yongjie Nie , YuanWei Zhu

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引用次数: 0

Abstract

Sufficient interfacial pressure between silicone rubber (SIR) insulation and cross-linked polyethylene (XLPE) in high-voltage cable accessories is the basic condition to ensure the normal operation of cable accessories. However, in the actual operation of cables and accessories, high-temperature aging and mechanical aging can cause the mechanical properties of SIR materials to decline, thus affecting the size of the insulation interface pressure. Firstly, the relaxation law of compressive stress of SIR material is obtained by measuring the compressive stress under force-thermal synergistic aging. Secondly, the time-temperature equivalent model is established according to the measured data to evaluate the service life of the cable accessories. Thirdly, the physical and chemical properties of SIR with different aging times are tested to analyze the change in its mechanical properties. Finally, the effect of temperature on the stress relaxation characteristics of SIR is calculated from the microscopic level by molecular simulation. The experimental results show that the compressive stress of SIR decreases first and then becomes stable with the increase of aging time due to the movement of molecular chains and chemical reactions in SIR. In addition, the compression stress relaxation rate of SIR increases with temperature. The aging life prediction model shows that when the relaxation coefficient of compressive stress drops to 50% of the initial value at the end of cable life, the service life of cable accessories at 70°C is about 24 years. The molecular simulation shows that the relaxation of the molecular chain of SIR is accelerated with the increase in temperature, and the stress relaxation of SIR material is accelerated on a macroscopic level. This research can provide a theoretical basis for the design and operation reliability of cable accessories.

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来源期刊

Polymer Degradation and Stability 化学-高分子科学

CiteScore

10.10

自引率

10.20%

发文量

325

审稿时长

23 days

期刊介绍： Polymer Degradation and Stability deals with the degradation reactions and their control which are a major preoccupation of practitioners of the many and diverse aspects of modern polymer technology. Deteriorative reactions occur during processing, when polymers are subjected to heat, oxygen and mechanical stress, and during the useful life of the materials when oxygen and sunlight are the most important degradative agencies. In more specialised applications, degradation may be induced by high energy radiation, ozone, atmospheric pollutants, mechanical stress, biological action, hydrolysis and many other influences. The mechanisms of these reactions and stabilisation processes must be understood if the technology and application of polymers are to continue to advance. The reporting of investigations of this kind is therefore a major function of this journal. However there are also new developments in polymer technology in which degradation processes find positive applications. For example, photodegradable plastics are now available, the recycling of polymeric products will become increasingly important, degradation and combustion studies are involved in the definition of the fire hazards which are associated with polymeric materials and the microelectronics industry is vitally dependent upon polymer degradation in the manufacture of its circuitry. Polymer properties may also be improved by processes like curing and grafting, the chemistry of which can be closely related to that which causes physical deterioration in other circumstances.