scholarly journals Dynamic Response of a Casting Crane Rigid-Flexible Coupling System to High Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Yunsheng Xin ◽  
Qing Dong ◽  
Qisong Qi ◽  
Qinglu Shi
Keyword(s):  
Alloy Steel ◽  
Dynamic Characteristics ◽  
Lagrange Equation ◽  
Design Stage ◽  
Main Beam ◽  
Test Bed ◽  
Influence Of Temperature ◽  
Direct Integration Method ◽  
Different Temperatures ◽  
Influence Of Temperature On

To determine the influence of temperature on the mechanical properties of crane metal structures, three Q355 alloy steel samples were processed and their elastic moduli were tested at different temperatures using a metal tension test bed. The constitutive equation for the elastic modulus of Q355 alloy steel at different temperatures was predicted using test data and a neural network algorithm. Based on crane structural characteristics and the principle of system dynamics, a coupling vibration model was established that included the crane flexible girder, cabin, trolley, crane, and temperature. System motion equations were established according to the Lagrange equation, and the approximate solution of nonlinear system vibration was solved by the direct integration method (the Newmark method). The dynamic characteristics of the main beam and cabin were analyzed at different temperatures, as well as safety during service. The results show that, with increasing temperature, the maximum midspan displacement of the main beam increases gradually, by 14.3%, 21.4%, and 57.1% at temperatures of 300°C, 400°C, and 600°C, respectively. The cabin vibration displacement increases with temperature, by up to 32.5% at 600°C, but the influence of temperature on cabin vibration acceleration is not obvious. It was concluded that the influence of temperature on the dynamic characteristics of the main beam must be considered during the design stage of cranes. The proposed model and analysis method provide a theoretical basis for the design of casting cranes according to temperature.

Research on dynamic characteristics of gear system considering the influence of temperature on material performance

2021 ◽  
pp. 107754632110026
Author(s):  
Zhou Sun ◽  
Siyu Chen ◽  
Xuan Tao ◽  
Zehua Hu
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
Poisson’S Ratio ◽  
Gear System ◽  
Poisson's Ratio ◽  
Effect Of Temperature ◽  
Time Varying ◽  
Influence Of Temperature ◽  
Meshing Stiffness ◽  
Influence Of Temperature On

Under high-speed and heavy-load conditions, the influence of temperature on the gear system is extremely important. Basically, the current work on the effect of temperature mostly considers the flash temperature or the overall temperature field to cause expansion at the meshing point and then affects nonlinear factors such as time-varying meshing stiffness, which lead to the deterioration of the dynamic transmission. This work considers the effect of temperature on the material’s elastic modulus and Poisson’s ratio and relates the temperature to the time-varying meshing stiffness. The effects of temperature on the elastic modulus and Poisson’s ratio are expressed as functions and brought into the improved energy method stiffness calculation formula. Then, the dynamic characteristics of the gear system are analyzed. With the bifurcation diagram, phase, Poincaré, and fast Fourier transform plots of the gear system, the influence of temperature on the nonlinear dynamics of the gear system is discussed. The numerical analysis results show that as the temperature increases, the dynamic response of the system in the middle-speed region gradually changes from periodic motion to chaos.

Thermal influence on the embryonic development and hatching rate of the flameback pygmy angelfish Centropyge aurantonotus eggs

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki
Keyword(s):  
Embryonic Development ◽  
Incubation Temperature ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Hatching Rate ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Thermal Influence ◽  
Hatching Rates

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.

scholarly journals Analysis of dynamic characteristics of viscoelastic frame structures

2019 ◽  
Vol 90 (1) ◽  
pp. 147-171
Author(s):  
Roman Lewandowski ◽  
Przemysław Wielentejczyk
Keyword(s):  
Eigenvalue Problem ◽  
Viscoelastic Material ◽  
Dynamic Characteristics ◽  
Nonlinear Eigenvalue Problem ◽  
Continuation Method ◽  
Frame Structures ◽  
Influence Of Temperature ◽  
Linear Eigenvalue Problem ◽  
Influence Of Temperature On ◽  
Parametric Analyses

Abstract Planar frame structures made of a viscoelastic material are considered in the paper. The technically very important structures made of a homogenous material are contemplated. A family of rheological models (classic and fractional) are used to describe the mechanical properties of the viscoelastic material. In particular, the dynamic characteristics of the structures are of interest. A numerically very efficient method is proposed to determine such characteristics. The method requires the solution to the linear eigenvalue problem for corresponding elastic structures and the solution to a nonlinear, algebraic equation. The presented method is much more efficient than other methods where, very often, the continuation method is used to solve the nonlinear eigenvalue problem. The influence of temperature changes on dynamic characteristics is analyzed using the frequency–temperature principle. The results of several parametric analyses are presented and discussed. For the first time, the influence of temperature on the dynamic characteristics of beams has been studied in detail.

Influence of Temperature on Field-Induced Reorientation Strain in Magnetic Shape Memory Alloy

2008 ◽  
Vol 575-578 ◽  
pp. 848-853
Author(s):  
Yu Ping Zhu ◽  
Guan Suo Dui
Keyword(s):  
Shape Memory ◽  
Magnetic Shape Memory ◽  
Magnetic Shape Memory Alloys ◽  
Influence Of Temperature ◽  
Single Crystal Specimen ◽  
Magnetic Shape Memory Alloy ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Special Concern ◽  
Theoretical Results

A constitutive model for magnetic shape memory alloys is developed through a combined consideration of micromechanical and thermodynamic theories. Of special concern is the influence of different temperatures on field-induced reorientation strain for a NiMnGa single-crystal specimen. The theoretical results are found to be in general agreement with experimental data. It is shown that the method is accurate and simple.

scholarly journals XXXVI. On the influence of temperature on the refraction of light

1858 ◽  
Vol 148 ◽  
pp. 887-894 ◽  
Keyword(s):  
Field Of View ◽  
Refractive Indices ◽  
Narrow Slit ◽  
Joint Research ◽  
Influence Of Temperature ◽  
Fine Wire ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
The Many ◽  
Cobalt Blue

Fraunhofer, in his original measurements of the fixed lines of the spectrum, noted the thermometer, and those who since his time have occupied themselves with the determi­nation of refractive indices, must have frequently noticed that changes of temperature affect the amount of refraction; yet of the many observations now on record, few have affixed to them the temperature at which they were made. Baden Powell has drawn out some refractive indices of the same substance taken at different temperatures, but remarks that the whole subject, both as to the facts of the case and as to their bear­ing on the theoretical formulæ, remains to be investigated. Among his beautiful researches on light, M. Jamin has recently published one or two experiments on refrac­tion, heat, and density; but, with this exception, he has left untouched the great question of the influence of temperature. Some years ago Baden Powell kindly lent his instrument to one of us for the pur­pose of investigating this question. It is described and figured in the Report of the British Association for 1839. It consists essentially of a small telescope moving on a circle graduated so finely, that by means of a vernier and magnifying glass it may be read to 10"; to ensure accuracy, there is a vernier at each end of the moveable arm: in front of the telescope are appliances for fixing any solid prism, or a hollow prism capable of containing liquids, in such a position that there may be seen through it a ray of light proceeding from a distant slit. The telescope may be moved till a fine wire fastened in the field of view is brought to coincide with any of Fraunhofer’s lines the prismatic spectrum thus obtained, and the angle indicated by the position of the telescope on the graduated circle may he read off. In our recent joint research, as we desired measure the positions of the extreme lines A and H, it was necessary to work with the full light of the sun; its mirrored image, therefore, was kept behind the narrow slit by a heliostat, and the eye was protected from the glare of the yellow ray by means of a cobalt-blue glass.

scholarly journals IV. On the influence of temperature on the heat of dissolution of salts in water

1885 ◽  
Vol 38 (235-238) ◽  
pp. 401-414
Keyword(s):  
Sodium Sulphate ◽  
Influence Of Temperature ◽  
Salt Melts ◽  
Different Temperatures ◽  
Anhydrous Compound ◽  
Influence Of Temperature On ◽  
Heat Of Dissolution ◽  
Vexed Question

The experiments described in this paper were undertaken in the hope of obtaining some light upon the vexed question of the condition in which a solid exists when dissolved in a liquid, and were directed more especially towards the investigation of the well-known remarkable phenomena exhibited by sodium sulphate. Crystallised sodium sulphate melts at about 34°, and at this temperature the salt begins to show signs of dissociation by depositing the anhydrous compound. According to Wiedemann, indeed, indications of change are observable at a few degrees lower. He finds by observation of the volume of the crystallised salt at different temperatures, that whereas slight expansion occurs from 17° to about 30°, contraction then sets in, at first slowly, then, at 33° to 34°, very rapidly, till the salt melts. The melted salt expands regularly in proportion as the temperature is raised to near 100°. Nicol has made experiments upon the expansion of solutions of the same salt, and with similar results.

scholarly journals The Influence of Temperature on the Efficacy of Polymerization of Composite Resin

2007 ◽  
Vol 8 (6) ◽  
pp. 9-16 ◽  
Author(s):  
Wedad Y. Awliya
Keyword(s):  
Composite Resin ◽  
Light Emitting Diode ◽  
Composite Resins ◽  
Significance Level ◽  
Light Emitting ◽  
Influence Of Temperature ◽  
Soft Start ◽  
Halogen Light ◽  
Different Temperatures ◽  
Influence Of Temperature On

Abstract Aim The purpose of this study was to investigate the effect of different temperatures on the efficacy of polymerization during the insertion of composite resin using different light curing units. Methods and Materials A total of 45 disc-shaped specimens were fabricated from Z250 composite resin (3M/ESPE, St. Paul, MN, USA) with 15 each prepared at three different temperatures (refrigerated to 5°C, room temperature at 25°C, and preheated to 37°C). Each of these temperature-controlled specimen groups of 15 were then subdivided into three groups of five specimens, according to the type of curing light used to polymerize them. Curing lights included a conventional halogen light (QTH) in two modes (continuous and softstart polymerization) and a light emitting diode (LED). The microhardness of the top and bottom surfaces of the specimens was determined using a Buehler Micromet II digital microhardness tester (Buehler, Dusseldorf, Germany). Data obtained was analyzed using two-way analysis of variance (ANOVA)/Post Hoc Tukey's test at a 0.05 significance level. Results As the temperature of composite resin increased, the top and bottom microhardness of the specimens also increased regardless of the type of polymerizing light used. The LED light produced a significantly better hardness on top and bottom surfaces of composite resin specimens polymerized at the three different temperatures. Effectiveness of cure at top and bottom surfaces of composite specimens was significantly reduced by using soft-start curing. Conclusion The use of pre-warmed composite resins might help to improve polymerization of composite resin especially at the deeper areas of a restoration which could result in an increase in the expected life of a composite restoration. Citation Awliya WY. The Influence of Temperature on the Efficacy of Polymerization of Composite Resin. J Contemp Dent Pract 2007 September; (8)6:009-016.

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