Strength Analysis and Structure Optimization of Gate Valve Body Based on Finite Element Software

Stress concentration zone and maximumdeformation zone ofgate valve at 1.6MPaworking pressure were found out according to strength calculationand analysisby ANSYSsoftware, which proceedsthe processes of modeling, meshing, constraintsdefine, applyingloadsand solving. Design variables,state variablesand optimize targetswere defined by target optimization design function of ANSYS Workbenchin ordertoreveal the influence law of eachdesign variable onthe gate valve body equivalent stress,and the optimal valuesof design variablescould be obtained after calculation. The valve structure was improved and stress concentration was reduced from the perspective of safety and economy,whichcouldprovidea referencefor reliable valvedesign.The shape of the valve body was optimized by topology optimization design in order to achieve the rational use of materials.Researchresultsshow that the maximum stress lies on both sides of the valve rib plateand the stress is beyond thematerial allowable value, but the valve body has little deformation.After optimization the maximum equivalent stress of valve body is decreasedby23.91%and the valvebodyhasuniformstress distribution, the mass of the valve body is reduced by1.4%as well. Material utilization is improvedeffectively,which indicates that the optimizationdesignbased onANSYS Workbenchis highly efficient and reliable

The Structure, Vibrational Spectra, and Thermal Expansion Study of AVO4 (A=Bi, Fe, Cr) and Co2V2O7

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO4 and Co2V2O7 are monoclinic at room temperature, FeVO4’s crystal structure is triclinic, and CrVO4 is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO4 occurred at 200 to 300 °C. The coefficient of thermal expansion (CTE) of Co2V2O7 was larger than that of the monoclinic structure BiVO4. The CTE of the tetragonal structure of BiVO4 was 15.27 × 10−6 °C−1 which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO4 was 2.84 × 10−6 °C−1 and was the smallest.</jats:p

Strength Analysis and Structure Optimization of Gate Valve Body Based on Finite Element Software

Stress concentration zone and maximumdeformation zone ofgate valve at 1.6MPaworking pressure were found out according to strength calculationand analysisby ANSYSsoftware, which proceedsthe processes of modeling, meshing, constraintsdefine, applyingloadsand solving. Design variables,state variablesand optimize targetswere defined by target optimization design function of ANSYS Workbenchin ordertoreveal the influence law of eachdesign variable onthe gate valve body equivalent stress,and the optimal valuesof design variablescould be obtained after calculation. The valve structure was improved and stress concentration was reduced from the perspective of safety and economy,whichcouldprovidea referencefor reliable valvedesign.The shape of the valve body was optimized by topology optimization design in order to achieve the rational use of materials.Researchresultsshow that the maximum stress lies on both sides of the valve rib plateand the stress is beyond thematerial allowable value, but the valve body has little deformation.After optimization the maximum equivalent stress of valve body is decreasedby23.91%and the valvebodyhasuniformstress distribution, the mass of the valve body is reduced by1.4%as well. Material utilization is improvedeffectively,which indicates that the optimizationdesignbased onANSYS Workbenchis highly efficient and reliable.</jats:p

The Structure, Vibrational Spectra, and Thermal Expansion Study of AVO4 (A=Bi, Fe, Cr) and Co2V2O7

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO4 and Co2V2O7 are monoclinic at room temperature, FeVO4&rsquo;s crystal structure is triclinic, and CrVO4 is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO4 occurred at 200 to 300 &deg;C. The coefficient of thermal expansion (CTE) of Co2V2O7 was larger than that of the monoclinic structure BiVO4. The CTE of the tetragonal structure of BiVO4 was 15.27 &times; 10&minus;6 &deg;C&minus;1 which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO4 was 2.84 &times; 10&minus;6 &deg;C&minus;1 and was the smallest

Fault section locating method and recovery strategy of pole-to-ground fault for medium voltage direct current (MVDC) distribution network

High-resistance clamping grounding is a common grounding mode of modular multilevel converter (MMC) based DC distribution network. Due to the current limiting function of grounding resistor, pole-to-ground fault can only cause limited steady-state fault current. Consequently, it is very difficult to locate fault section. Besides, there are a few research works on pole-to-ground fault recovery strategy of a DC distribution system. This study purposes a fault criterion based on DC pole-to-ground voltage amplitude and changing rate. Then, by extracting polarities of a DC feeder current travelling wave using the method of wavelet transform modulus maximum, a rapid fault section locating method is presented. Furthermore, a feasible pole-to-ground fault recovery strategy is introduced, which can reduce outage range and time on the premise of guaranteeing system stability. The performances of the proposed methodologies were validated by numerical simulation

An Efficient Methodology for License Plate Localization and Recognition with Low Quality Images

Abstract It is challenging to find an effective license plate detection and recognition method due to the different conditions during the image acquisition phase. This paper aims to develop a new accurate and efficient method based on color difference and SVM recognition model that yields better performance for vehicle images under low quality. The proposed method is tested with 200 images which involve many difficult conditions, such as low resolution, night-lighting, dirt, complicated background, and distortion problems. The experimental results demonstrate very satisfactory performance for license plate detection in terms of speed and accuracy and are better than the existing methods like edge detection or HSV color conversion method. The overall probability of localization is close to 100%, with a false recognition rate of 2%.</jats:p