As the basic materials with specific properties, fabrics have been widely applied in electromagnetic (EM) wave protection and control due to their characteristics of low density, excellent mechanical properties as well as designability. According to the different mechanisms and application scenarios on EM waves, fabrics can be divided into three types: EM shielding fabric, wave-absorbing fabric and wave-transparent fabric, which have been summarized and prospected from the aspects of mechanisms and research status, and it is believed that the current research on EM wave fabrics are imperfect in theory. Therefore, in order to meet the needs of different EM properties and application conditions, the structure of fabrics will be diversified, and more and more attentions should be paid to the research on structure of fabrics that meets EM properties, which will be conductive to guiding the development and optimization of fabrics. Furthermore, the application of fabrics in EM waves will change from 2D to 3D, from single structure to multiple structures, from large to small, as well as from heavy to light.

Based on the wave absorption model of 3D woven fabric and the zero-reflection equations, a new structural design method of 3D electromagnetic (EM) wave-absorbing woven fabrics was obtained. The 3D woven fabrics fabricated by the proposed method had the structure of a bidirectional angle interlock. Continuous S-2 glass fibers were used as the matching layer of this 3D woven fabric, and continuous carbon fibers were used as the absorbing layer. The absorbing layer satisfied the equivalent EM parameters under the condition of zero reflection. The results of the simulation and experiment showed that the performance trends of the 3D wave-absorbing fabric obtained by this method were consistent with the theory, which verified the correctness of the structure design method. The 3D fabrics obtained by this method have the advantages of wide absorbing frequencies and good absorbing performance (−20 dB). This structural design method also has theoretical guiding significance for the development of 3D wave-absorbing fabrics.

Electric spark and femtosecond-laser surface texture are very effective in antifriction systems, but there are few applications and studies in dry friction. In this study, a groove texture was prepared on the surface of 0Cr17Ni7Al stainless steel via electric spark and femtosecond laser, respectively. The tribological properties of the two groove textures under different collision frequencies with the groove were studied under the condition of dry friction. The results show that the friction coefficient of the groove texture prepared by EDM and femtosecond laser is lower than that of the untextured surface. However, this does not mean that every groove-texture design will reduce wear rate. In addition, the groove texture seems to produce different tribological properties under different preparation methods. It is found that in the friction process of the same load, time and linear velocity, different collision frequencies will affect the friction and wear properties of the surface.

Friction and wear are the main forms of material surface failure. Surface modification is very effective in friction reduction and wear resistance systems. Therefore, as a method of surface modification to improve the tribological properties of materials, surface texture has been widely loved by scholars. However, most scholars use laser and other processing methods to prepare the surface texture. Although these processing methods have a high preparation efficiency, they cannot obtain a surface texture with high dimensional accuracy due to their non-contact processing characteristics. Moreover, previous studies on different surface texture preparation methods are insufficient. Scholars have not fully studied the size parameters of surface modification. Micromachining is a contact machining method. It has high dimensional accuracy. Therefore, the surface groove texture of 0Cr17Ni7Al material commonly used in sliding bearings was prepared by micromachining in this paper. Under dry friction conditions, the effects of different groove widths on the tribological properties of surface texture were studied. The results show that the friction coefficient at the 0.6 mm-wide groove texture is the lowest, σ = 0.632. The minimum wear rate is ω = 3.351 × 10⁻⁴ mm³/(N·mm). The friction coefficient and wear rate of all groove textures are lower than those of untextured surfaces. It can be judged that the groove texture prepared by micromachining has good friction reduction and wear resistance under the same load, time, and linear speed. With the increase of the groove width, the friction coefficient and wear rate of groove texture decrease first and then increase.

High accuracy prediction of degradation trend provides valuable information in establishing reasonable maintenance decision-making with the goal of improving the maintenance efficiency and avoiding sudden downtime. The extraction of degradation features and the prediction algorithm are the key factors in degradation trend prediction. In this work, based on composite multiscale grey entropy (CMGE) and dynamic particle filter (PF), a novel prediction architecture is proposed to improve accuracy under different working conditions. The CMGE is proposed as the degradation feature indicator extracted from rolling bearing vibration signal. The dynamic PF is proposed to predict the degradation trend of rolling bearing. Three rolling bearing accelerated life tests were conducted to evaluate the performance of the proposed method for rolling bearing degradation trend prediction. Experimental results demonstrate CMGE has good monotonicity and weak data length dependence, which can effectively describe the degradation trend of rolling bearing, and the proposed dynamic PF achieves higher prediction accuracy than the traditional PF and GM model, respectively.