Influence of automobile sealing rib structure on sound insulation performance and optimization of section parameters

2021 ◽  
Vol 263 (1) ◽  
pp. 5769-5779
Author(s):  
Xian Wu ◽  
TengLong Jiang ◽  
JianWang Shao ◽  
GuoMing Deng ◽  
Meng Zhao
Keyword(s):  
Cross Section ◽  
Great Influence ◽  
Sound Quality ◽  
Optimal Combination ◽  
Sound Insulation ◽  
Section Shape ◽  
Rib Structure ◽  
The Difference ◽  
Orthogonal Optimization ◽  
Insulation Performance

The door sealing strip plays an important role in the sound insulation of the car, and its sound insulation performance has a great influence on the sound quality and comfort of the vehicle. The sound insulation performance of the seal can be analyzed by Finite Element-Statistic Energy Analysismodel. There are great differences in the cross-section of the door sealing strip system at different positions, which leads to the difference of sound insulation. Therefore, it is very important to study the sound insulation performance of the sealing strip by studying the parameters of different sections. This paper explores the influence of the structure of automobile sealing rib on the sound insulation performance. Taking the sound power of the receiving end of the sealing strip as the index, the orthogonal optimization test is carried out for the simplified section shape of the door seal strip: the wall thickness of the sealing strip, the height of the sealing strip and the rib length. The optimal combination of a set of sealing strip sections is established, and the sound insulation performance of the sealing strip is improved.

Dynamic Characterization of Free Torsional Subsystem by Galerkin’s Approximate Method and its Correction

2015 ◽  
Vol 809-810 ◽  
pp. 604-609
Author(s):  
Andrzej Buchacz
Keyword(s):  
Complex System ◽  
Complex Systems ◽  
Approximate Method ◽  
Cross Section ◽  
Great Influence ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Mechatronic Systems ◽  
Resonance Frequencies ◽  
The Difference

Studying the diagrams of characteristics of complex subsystem of mechatronic one it has been determined that in case of approximate method the resonance frequencies cover with those which have been determined with exact method. However the values of the characteristic in other areas are different. Therefore there is the mistake of approximate method, which in case of studying the single systems does not have any influence because in resonance areas the characteristic values of the system approach to the infinity. However the difference in values of flexibility within two methods has the great influence on the result of complex systems. The main subject of deliberation was to determine the flexibility of the complex system with constant cross section using the exact and approximate that means Galerkin's method. The mechanical and/or mechatronic system composed from many mechanical subsystems having the same length and variable cross section, loaded by the focused moment was analysed. One case of attachment the complex system that means free torsional vibrating bar were examined. That why it was necessary to correct the results of approximate method. The problems presented in this paper, that means the analysis of subsystem of mechatronic and mechanical complex systems is however the introduction to the synthesis of torsional vibrating mechatronic systems with assumed frequency spectrum.

Study on Special Shaped Polyester Fibers and Development of Products

2021 ◽  
Vol 8 (3) ◽  
pp. 17-22
Author(s):  
Yeqian Ge ◽  
Qin Deyan ◽  
Wang Hongfang ◽  
Tu Jianhong ◽  
Wang Xuefei ◽  
...  
Keyword(s):  
Cross Section ◽  
Natural Fibers ◽  
Great Influence ◽  
Circular Cross Section ◽  
Synthetic Fibers ◽  
Pet Fabric ◽  
Knit Fabrics ◽  
Section Shape ◽  
Pet Fibers ◽  
Profiled Fibers

Non-circular profiled fibers are generally synthetic fibers that have a modified cross-section shape, which are created to mimic natural fibers or to obtain special properties. The shape of the cross-section has great influence on the properties of profiled polyester (PET) fibers and their fabrics. The structure and properties of flat-shaped and hexagonal-shaped profiled PET fibers and ordinary PET fibers, as well as the properties of their knit fabrics were characterized. Experimental results showed that air permeability, heat retention, and wrinkle resilience of profiled PET fabrics were better than that of circular a cross-section PET fiber fabric, while the circular cross-section PET fabric was softer than the profiled PET fiber fabrics.

Study on the Effect of Thermal Design of Plane Mould on the Mechanical Properties of Epoxy Sheet Molding Compounds

2011 ◽  
Vol 221 ◽  
pp. 321-325 ◽  
Author(s):  
Jian Li ◽  
Zhi Xiong Huang ◽  
De Liang Jin
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Epoxy Resin ◽  
Cross Section ◽  
Great Influence ◽  
Thermal Design ◽  
Fiber Distribution ◽  
Molding Compounds ◽  
Mould Cavity ◽  
The Difference

The heating style of the plane mould has great influence on the mechanical properties of E-SMC parts. In this paper, the temperature distribution of the plane mould (general heating style and thermal optimized heating style) and the mechanical properties and the cross section morphology of E-SMC samples were systematically studied. The results showed that there existed 30°C difference between the highest temperature point and the lowest temperature point in the general heating mould cavity, the difference of flexural strength between the samples cut from the centre and those cut from the corner was about 140MPa, otherwise, the fiber distribution of the fracture cross section was extremely uneven and the fibers were poorly adhered with epoxy resin. While, in the thermal optimized mould cavity, the surface temperature was much more even and the difference between the highest temperature point and the lowest temperature point was less than 10°C. And the flexural strength between the samples cut from the centre and those cut from the corner was close to be 320MPa. The fiber distribution of the fracture cross section was even and the fibers were well adhered with epoxy resin.

Test of Cross-Section Shape of Air-Liquid Interface in Microgrooves With Micro-PIV Method

2011 ◽  
Author(s):  
Xuelei Nie ◽  
Xuegong Hu ◽  
Tao Wang ◽  
Dawei Tang
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Great Influence ◽  
Liquid Interface ◽  
Polynomial Curves ◽  
Micro Piv ◽  
Cross Section Shape ◽  
Section Shape ◽  
The Cross ◽  
Air Liquid Interface

Evaporation of liquid meniscus formed in microgrooves is associated with very high heat transfer rates, but the cross-section shape of air-liquid interface has a great influence to the heat transfer in microgrooves. But the real cross-section shape of interface in microgrooves is still unknown for us. In this work, the micro-PIV (Particle Image Velocimetry) method is used to test the cross-section shape of air-liquid interface in microgrooves. In the experiment, the camera is focus on different planes from top of the microgrooves to the bottom of the microgrooves. In each plane, we can see the boundary between the air and liquid through small particles added into the liquid. The positions of boundary in each plane for a given cross section are drawn in two-dimension coordinate. Then the cross-section shape of interface in microgrooves can be seen from the fitting curve. The results show that the cross-section shapes of the interface in microgrooves are not round, but polynomial curves. The curvature of interface in microgrooves changes along a single curve. Besides, the polynomial curves also vary along axial direction of the microgrooves. The variations are more obvious in vertical microgrooves than in horizontal microgrooves.

scholarly journals Designing for People’s Safety on Flooded Streets: Uncertainties and the Influence of the Cross-Section Shape, Roughness and Slopes on Hazard Criteria

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2119
Author(s):  
Luís Mesquita David ◽  
Rita Fernandes de Carvalho
Keyword(s):  
Cross Section ◽  
Overland Flow ◽  
Rectangular Cross Section ◽  
Safety Hazard ◽  
Cross Section Shape ◽  
Section Shape ◽  
Flood Flows ◽  
The Cross ◽  
Flooding Risk

Designing for exceedance events consists in designing a continuous route for overland flow to deal with flows exceeding the sewer system’s capacity and to mitigate flooding risk. A review is carried out here on flood safety/hazard criteria, which generally establish thresholds for the water depth and flood velocity, or a relationship between them. The effects of the cross-section shape, roughness and slope of streets in meeting the criteria are evaluated based on equations, graphical results and one case study. An expedited method for the verification of safety criteria based solely on flow is presented, saving efforts in detailing models and increasing confidence in the results from simplified models. The method is valid for 0.1 m2/s 0.5 m2/s. The results showed that a street with a 1.8% slope, 75 m1/3s−1 and a rectangular cross-section complies with the threshold 0.3 m2/s for twice the flow of a street with the same width but with a conventional cross-section shape. The flow will be four times greater for a 15% street slope. The results also highlighted that the flood flows can vary significantly along the streets depending on the sewers’ roughness and the flow transfers between the major and minor systems, such that the effort detailing a street’s cross-section must be balanced with all of the other sources of uncertainty.

scholarly journals On the shape of cicada’s wing leading-edge cross section

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rachel M. Starkweather ◽  
Svetlana V. Poroseva ◽  
David T. Hanson
Keyword(s):  
Cross Section ◽  
Insect Flight ◽  
Leading Edge ◽  
Flight Performance ◽  
Cross Section Shape ◽  
Section Shape ◽  
First Time

AbstractAn important role that the leading-edge cross-section shape plays in the wing flight performance is well known in aeronautics. However, little is known about the shape of the leading-edge cross section of an insect’s wing and its contribution to remarkable qualities of insect flight. In this paper, we reveal, in the first time, the shape of the leading-edge cross section of a cicada’s wing and analyze its variability along the wing. We also identify and quantify similarities in characteristic dimensions of this shape in the wings of three different cicada species.

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