Research Progress of Logarithmic Crown of Bearing Roller

In view of the complexity of the problem of the logarithmic crown of the bearing roller, this paper introduce the design, processing and measurement of the logarithmic crown, analyze the research progress in various aspects, and explore the unsolved problems

Study on the Load Sharing Capability of Closed-loop Gear Transmission in Braiding Machine

The static model is established based on the structural characteristics of closed loop gear transmission. The influence law of manufacturing and assembly error with load sharing coefficient was researched. The formula among transmission gear errors and load sharing coefficient is established. According to the formula of error coupling in the same angular frequency, transmission errors in closed loop gear transmission are coupled. The measure for reducing the transmission error is put forward. The study provides a theoretical basis for the design of high speed braiding machine

Research Progress of Logarithmic Crown of Bearing Roller

In view of the complexity of the problem of the logarithmic crown of the bearing roller, this paper introduce the design, processing and measurement of the logarithmic crown, analyze the research progress in various aspects, and explore the unsolved problems

Study on the Load Sharing Capability of Closed-loop Gear Transmission in Braiding Machine

The static model is established based on the structural characteristics of closed loop gear transmission. The influence law of manufacturing and assembly error with load sharing coefficient was researched. The formula among transmission gear errors and load sharing coefficient is established. According to the formula of error coupling in the same angular frequency, transmission errors in closed loop gear transmission are coupled. The measure for reducing the transmission error is put forward. The study provides a theoretical basis for the design of high speed braiding machine

Geometrical model of 3D layer-to-layer angle-interlock woven preforms with oblique structure

The original configuration of 3D layer-to-layer angle-interlock (LLA) woven fibers cannot be maintained during matrix impregnation and is unstable when the composite is subjected to loading. The fibers in the yarn are susceptible to lateral sliding, resulting in deformation of the textile geometry. The initial modulus of the composite in the warp direction is smaller and can be inconsistent owing to the unstable geometry of the fabric. A stable 3D layer-to-layer angle-interlock (SLLA) fabric was devised by constructing a denser yarn arrangement, and the properties of this new structure were investigated in this study. The geometric parameters of this novel reinforcing structure were mathematically modeled, and the results were validated experimentally. The results showed that the SLLA structure was more stable than that of the LLA fabric. The experimentally determined structural parameters were in good agreement with the theoretically calculated values

Stratigraphy and tectonic setting of Laochang massive sulfide deposit in the North Qinling belt, central China

The Qinling orogenic belt in central China is the northernmost orogenic collage within the Tethyan domain, which records the evolution of the Paleo-Tethys Ocean. A suite of volcano-sedimentary rocks containing rare fossils and several VHMS deposits is exposed along the North Qinling belt. These units are separated into the Caotangou, Xieyuguan and Erlangping groups from west to east. Systematic studies on the facies and geochemistry demonstrate that the Caotangou Group represents a bimodal volcanic sequence formed in a backarc setting with massive sulfide horizons closely associated with a siliciclastic-felsic volcanic sequence. SHRIMP and LA-ICP-MS zircon U-Pb data from rhyolite and tuff of the Caotangou Group indicate that the volcanism took place between ca. 440¿406 Ma, which is similar to the dacite and andesitic basalt of the Xieyuguan Group. The Precambrian xenocrystic zircon grains suggest that the subduction-related crustal source of those volcano-sedimentary rocks in the North Qinling belt is closely related to the Qinling Group. Based on the combination of previous fossil ages, U-Pb dating of volcanic rocks and geochemistry of lavas and sulfides, we suggest that a southward-facing subduction-accretionary system developed along the southern margin of the North China plate during 490¿410 Ma. Subduction-related calc-alkaline magmatism continued until at least ca. 410 Ma before collision of the arc with the Qinling terrane to the south during the Early Devonian led to the continent-continent collision between the Qinling terrane and North China craton in the Late Carboniferous

A deformation model and draping behavior analysis of plain weave fabric with low-twist yarn on continuous surface

Fiber-reinforced composites have been widely applied in aerospace, transportation and other industrial applications. An effective method shaping the complex performs is draping plain fabrics on the mandrel surface. However, it is a challenge to realize and predict accurately the deformation of fabric. To establish an accurate deformation mode, plain weave fabrics with low-twist yarn were classified into a stable structure that are not easy to deform and an unstable structures with large deformability based on microstructure characteristics. A variable microstructure unit-cell model has been established to analyze the variation of fabric geometry and performance during deformation. To analyze the draping behavior of fabric with large deformation, a four-node unit was used to mesh the fabric, and then each node on the fabric was mapped to the mandrel surface. The deformation of fabric after draping was simulated by the continuous change of the unit mesh. Analysis results showed that the thickness of preform decreases with the increase of the major-axis of the yarn cross-section, and the formability of fabric increases with the increase of fabric pitch. The accuracy and effectiveness of the geometric mapping method are verified by the fabric drape experiment

Research and Application of Mathematical Model of Transmission Grating Signal Lissajous Figure

In this paper, the working principle of the grating measurement system is combined with the Fourier analysis method of Moiré fringe to establish the mathematical model of the grating signal Lissajous figure to know the quality of the grating signal intuitively. The Mathematica numerical analysis software is used to obtain the graphics of the model, and the correctness of the relationship between the parameters of the grating measurement system and the Lissajous figure equation of the grating signal is verified. The influence of the grating pair angle α on the output voltage signal and Lissajous figure of the grating measurement system is studied. The results show that the intensity of the two-phase output electrical signal decreases gradually with the increase of the deviation of the angle α of the grating pair, but the equal-amplitude of the two-phase output electrical signal does not change; Meanwhile, the shape of the grating signal Lissajous figure gradually changes from the ideal circle to the non-ideal ellipse, until a straight line with a strip slope of 135° is formed

A Structural Design Method of 3D Electromagnetic Wave-Absorbing Woven Fabrics

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