Modeling FGM brake disk against global thermoelastic instability (hot‐spot)

Abstract

Key words Thermal instability, functionally graded materials, non-stationary heat flux, frictional heat sources, nonstationary heat convection. This paper deals with study of the global thermoelastic instability of brake disk made of either the isotropic homogeneous metal matrix composite (MMC) or the isotropic inhomogeneous functionally graded material composite (FGM). The main idea of the FGM composite is a smooth variation of material properties due to continuous change in microstructure. The estimates in diffusion equation are characterized both by non-stationary heat flux and non-stationary heat convection terms enhanced by the characteristic frictional heat sources. Global instability is characterized by the Schaefer-Papkovich condition. Application of functionally graded A356R-based composite to brake disk structure prevents loss of global stability in contrast with homogeneous A356R composite and stainless steel ASTM321 brake disk which guaranties safety and durability of the braking system.

Thermoelastic instability of a functionally graded layer interacting with a homogeneous layer

“…Their studies showed that FGMs could improve the contact stability in the frictional sliding system through an optimal gradient index of FGMs. Hernik [35] dealt with the study of the global thermoelastic instability of a brake disk made of either the isotropic homogeneous metal matrix composite or FGMs. For the static thermoelastic instability, Mao et al [36] investigated the stability behaviors for three types of material combinations between an FGM layer and a homogeneous half-plane.…”

Thermoelastic instability of functionally graded materials in frictionless contact

“…Their studies revealed that an optimal gradient index of FGMs can lead to a maximum critical speed and enhance the performance of the frictional sliding system. Hernik [24] considered the application of functionally graded A356R-based composite to the brake disk structure in order to prevent the thermoelastic instability of the braking system. However, the works on the static thermoelastic instability are quite limited despite their importance in the design of FGM structures.…”

A Study on Coupled Thermo-Elasto-Plastic-Damage Dissipative Phenomena: Models and Application to Some Innovative Materials

“…In the example under consideration the first eight eigenvalues are shifted to the safe range 1 = −430 917, defined by the Schaefer-Papkovich condition (124), Figure 14 Hoop stress distribution in homogeneous A356R brake disk, after Hernik [45]. which means that the conservative loadings: angular velocity and temperature do not lead to lost of global stability.…”

“…Generalized hoop stress distribution in ASTM 321 homogeneous stainless steel brake disk, after Hernik [45]. Maximum temperature of the FGM brake disk (Fig.…”