Life evaluation of a combustion chamber by thermomechanical fatigue panel tests based on a creep fatigue and ductile damage model

Abstract

The inner liner of a combustion chamber of a cryogenic liquid rocket engine is exposed to a high load induced by the high temperature of the hot gas and the low temperature of the coolant. The high load causes some inelastic strain that accumulates with each operational cycle until the fracture or rupture of the inner liner. A model that can reproduce the propagation of damage under a thermally cycled load is essential for precisely predicting the chamber life. However, the damage propagation phenomenon or the quantitative value of the damage was so far not fully discussed using the damage data obtained from basic testing of a rocket chamber material. The purpose of the present study was to investigate a precise prediction model based on damage mechanics for simulating the damage propagation of a rocket chamber material. In this study, low cycle fatigue test data at a high temperature (900 K) were analyzed, and damage models that could reproduce the damage propagation under cyclic load conditions were investigated. Then the parameters were identified to reproduce uniaxial test data. These damage models were also subject to a finite element method analysis of a thermomechanical fatigue panel test in order to quantitatively evaluate the deformation, damage propagation, and life of a chamber wall. The analysis of low cycle fatigue test data at 900 K suggested a specific model that could precisely reproduce the damage propagation phenomenon and the basic material test data. From the results, it was confirmed that the model could predict the location of crack initiation.

Combustion Chamber Fatigue Life Analysis for Reusable Liquid Rocket Engines (LREs)

“…where "𝐷 6v6w: " denotes the total amount of brittle and ductile damage (equation expressed in its incremental form). The basic material parameters: "𝜎 e ", "E", "S", "s", as highlighted in Table 5, are experimentally acquired from uniaxial tension-compression LCF tests, as in [21]. These are subsequently integrated into damage evolution equations in the post-processing CC's fatigue life evaluation, to allow an assessment of the crack initiation and propagation.…”

Review on Creep Phenomenon and Its Model in Aircraft Engines

“…The estimation of the number of operating cycles for the availability of the inner wall material was based on the assessment of the absolute values of the creep of the wall material and the accumulated inelastic deformation without creep in a single engine cycle. Masuoka and Riccius [58] devised a system based on damage mechanics that can properly mimic the damage propagation phenomena, which was utilized to model the damage propagation of rocket cabin materials. A viscoplastic model [59], a creep-fatigue model, and a ductile damage model [14] were combined with the model.…”

“…Creep life calculation by constitutive equation [56], [58], [60], and [70] Creep life calculation [29], [31], [32], [34], [36], [38], [48], [49], and [71] Creep-fatigue life [23], [25], [39], [50], [41], [42], [46], [47] and [54] Figure 15: Appearance of TBC sample after cyclic heating test [74].…”

An integrated unified elasto-viscoplastic fatigue and creep damage model with characterization method for structural analysis of nickel-based high-temperature structure

“…Generally, the fatigue damage is accumulated by transgranular defects occurring under cyclic loading conditions, and the creep damage is accumulated by intergranular voids caused by dwell time (i.e., constant loading conditions) (Murakami, 2012). To predict such damage behavior, the number of literature established Continuum Damage Mechanics (CDM) theory-based damage model (Basirat et al., 2012; Cano and Stewart, 2021; Gholami et al., 2021; Naderi et al., 2013), and under high-temperature conditions, the advance of solution reliability can be expected through the integration with the elasto-viscoplastic model (Masuoka and Riccius, 2020). In addition, high-temperature structures are subjected to both cyclic and dwell loading simultaneously during operations.…”