Frictional Heating during Braking of the C/C Composite Disc

Abstract

An analytical model to determine temperature in a single brake disc of multi-disc system is proposed. The model considers the convective cooling on the lateral surfaces of the disc and structure of composite friction material. Calculations were carried out for a disc made of carbon friction composites material Termar-ADF. The influence of heat transfer with environment, length of bundles with fibers, and concentration of fibers in composite on the temperature of the disc was investigated during single braking with constant deceleration.

Inverse Thermoelastic Analysis of a Cylindrical Tribo-Couple

“…It is shown that the maximum relative error of the computed values in comparison to the corresponding values imposed in the direct problem (19) falls within 1.8%, which confirms the stability of the proposed solution algorithm with respect to the small errors in the input data. Due to the fact that the solutions to well-posed direct problems are stable with respect to small errors in the input data, the error in computing the thermal stresses, strains, and displacements by using the thermal loading (19) of the one computed by solving the inverse problem can be dismissed.…”

“…Such analysis is a key point in evaluating the characteristics of frictional interaction and material properties and is vital for both mechanical engineering and material science. Therefore, many practical cases of thermoelasticity problems, those that focus on the coupling between the thermal and mechanical fields, are concerned with frictional heating induced by the roughness of the contacting surfaces of interacting solids (see, e.g., [ 17 , 18 , 19 ]).…”

“…The distribution of the dimensionless circumferential strain ε(τ) = ε (2) ϕϕ (k 2 , τ) × 10 4on the outer surface ρ = k 2 is shown in Figure2a. The strain was computed from the direct problem under the thermal loading(19) for the following parameters R0 = 5.0 × 10 −2 [m], R 1 = 3.5 × 10 −2 [m], R 2 = 6.0 × 10 −2 [m], n 1 = 10 −3 [m/GPa], n 2 = 10 −4 [m/GPa], R = 5.0 × 10 −3 [m 2 × K/Wt], R * = 1.1 × 10 −3 [m 2 × K/Wt]; σ * =10 2 [MPa], T 0 = 20 [K], B = 200 [K], C = 10 2 , f = 0.25, ω = 1.22 [rad/s], and τ m = 2.5.…”

“…Figure2a. The strain was computed from the direct problem under the thermal loading(19) for the following parameters…”

Analytical Determination of the Brake Temperature Mode during Repetitive Short-Term Braking

“…These are mainly linear boundary value problems of heat conduction [ 17 ]. The exact obtained solutions to such problems during single braking cases are in the form of closed engineering formulas and allow for instant assessment of the temperature during braking under light conditions with sufficient accuracy; when the volumetric and the average temperatures of the friction surface do not exceed 100 °C and 200 °C, respectively [ 18 , 19 , 20 ]. Under heavy and medium braking conditions, when the volume temperature reaches values above 250 °C, the friction coefficient and properties of the friction pair materials change significantly due to the influence of temperature; therefore, numerical methods are used [ 21 , 22 ].…”