[雙語翻譯]車輛工程外文翻譯--汽車盤式制動器的熱機(jī)械性能

1、2500 英文單詞， 英文單詞，12500 英文字符，中文 英文字符，中文 3800 字文獻(xiàn)出處： 文獻(xiàn)出處：Dhir D K. Thermo-mechanical performance of automotive disc brakes[J]. Materials Today: Proceedings, 2018, 5(1): 1864-1871.Thermo-mechanical performance of automotive

2、 disc brakesDaanvir Karan DhirAbstractThe kinetic energy of the vehicle is converted into mechanical energy while braking which leads to heat dissipation and temperature rise of the disc and the disc-pads. The aim of thi

3、s investigation was to study the rise in temperature of an automotive disc brake at the time of braking and its effect on disc durability using finite element method. Application of a specified braking torque on the roto

4、r led to generation of heat flux. The heat flux generated and the heat transfer coefficient taken into consideration were numerically analyzed, which were then used to calculate the rotor rigidity, maximum temperature ri

5、se on the disc rotor. The rotor was further loaded with thermo-mechanical cyclic stresses which were used to analyze the durability and fatigue factor of safety of disc. The influence of variations in disc rotor geometry

6、 i.e. holes and airfoil vents in comparison to a simple flange type disc were studied and their effect on maximum temperature rise and disc durability has been investigated by modeling and conducting FEM techniques in So

7、lid works and ANSYS respectively.Keywords: Braking torque; disc brake; heat flux; thermo-mechanical analysis; thermal fatigue1. IntroductionA braking system is one of the most important safety components of an automobile

8、. It is mainly used to decelerate vehicles from an actual speed to a desired speed. Friction based braking systems are still the common device to convert kinetic energy into thermal energy, through friction between the b

9、rake pads and the rotor faces [3-7].Disc brakes operate with less fade as compared to drum brakes under the same conditions. An additional advantage of disc brakes is their linear relationship between braking torque and

10、pad/rotor friction coefficient [3].Advantages of disc brakes over drum brakes have led to their universal use passenger-cars and light-trucks. Brake friction materials i.e. brake pads and linings are made from materials

11、which have a high coefficient of friction. The choice of material depends on the braking application, but it needs to absorb and disperse large amount of heat without the braking performance being adversely affected [3].

12、 Thermal analysis is a primordial stage in the study of the brake systems because the temperature determines thermo-mechanical behaviour of the structure [2]. Braking performance of a vehicle can be significantly affecte

13、d by the temperature rise in the brake components. High temperatures during braking may cause brake fade, premature wear, brake fluid vaporization, bearing failure, thermal cracks and thermally-excited vibration. Therefo

14、re, it is important to predict the temperature rise of a given brake system and assess its thermal performance in the early design stage [1].During stop braking, the temperature does not have time to be stabilized in the

15、 disc. It is essential to evaluate the thermal gradients which require a three-dimensional modelling of the problem. The thermal loading is calculated by a heat flux entering the disc through the brake pads. The large am

16、ount of heat generated at the pad/disc interface during emergency braking indisputably evokes non-uniform temperature distributions in the domain of the rotor [2].The energy dissipated in the form of heat can generate ri

17、ses in temperature ranging from 300?C to applicable with ambient temperature being constant.? The kinetic energy of the vehicle is lost in the form of thermal energy dissipated by the disc rotors.? The tyres come to rest

18、 with a consistent deceleration.? The thermal conductivity of the material used for the analysis is uniform throughout [5].? Heat flux on each front wheel is applied on one side of the disc on the swept area, in a direct

19、ion normal to the friction surface [5].? Radiative heat transfer is included in terms of an equivalent radiative heat transfer coefficient [7].2.1.2 Average braking powerq?= = = 16532.63 Watt （1）K(1 ?

20、 s).u.a.w.36002(778)1(1 ? 0.08) × 16.67 × 7.84 × 275 × 9.812 × 9.81q(?)= q? × 0.60 × 0.50 × 0.50 × 0.90 = 2231.90 WattWhere,0.60 = weight distribution on front wheels0.50 = si

21、nce one front brake rotor is considered0.50 = since one side of the rotor is considered0.90 = 10% heat lost (heat lost coefficient)Swept Area of Disc Rotor = (D² ? d²) （2）π4= [(0

22、.16) ² - (0.116) ² = 0.0184 m²）π4Stopping Time, t = = = 2.12 sec.u𝑎16.677.84Final Braking Power, P = = = 1052.78 Nm/sec.q(?)t2231.902.12Heat Flux = = =57216.62 W/ m²powerArea1052.780.01842.

23、1.3. Braking forceP = [ lp?p] (3)1AmcFp2Therefore, P = [250×6×0.8]= =2.445 MPa1490.6251200490.625Considering 2 cylinders in parallel, so force on each cyli

24、nder, Fc = 1200/2 = 600 N2.1.4. Braking torqueRm=（4）23𝐷1³ - 𝐷2³𝐷1² - 𝐷2²Rm = 0.1413 (D1 = 0.164 m; D2 = 0.112m)Braking Torque, Mf[6] = 2 Fcf Rm

25、 (5)= 2 × 600 ×0.6 ×0.1413 = 101.76 Nm2.1.5. Convective heat transfer coefficientHeat transfer coefficient for a disc rotor having laminar type heat flow (Re> 2.4×10e5) is given by [7]