MI-SiCf/SiC复合材料开孔拉伸性能孔径效应研究

doi:10.15541/jim20250347

摘要/Abstract

摘要：

为满足航空发动机热端部件对熔渗(MI)工艺SiC_f/SiC复合材料含孔结构的设计需求, 本研究制备了无孔试样以及五种孔径(D=1~9 mm)的开孔试样, 并开展室温拉伸实验。通过数字图像相关与声发射技术, 实时监测了全场应变与内部损伤, 系统揭示了孔径对损伤起始与演化的影响规律。通过建立三维有限元模型, 分析了材料非线性行为与孔边应力集中、孔-边缘应力干涉之间的竞争机制。研究结果表明, 开孔拉伸强度与孔径呈非线性关系: 当孔径D≤3 mm时, 强度随孔径增大而缓慢上升, 孔径D>3 mm时强度随孔径增大而迅速降低; 试样宽度与孔径之比(W/D)存在临界阈值, 当W/D<3时, 孔与边缘应力集中相互干涉, 导致承载能力急剧下降, 几何效应主导失效。损伤起始应力随孔径增大而降低, D≤3 mm的小孔试样损伤演化仍具顺序性, D>3 mm的大孔试样则表现为多种损伤模式并发。有限元分析进一步揭示, 材料进入非线性阶段后, 应力峰值会从孔边偏移, 使得孔径为1~2 mm的试样因孔边应力区与材料缺陷重合而早期失效。大孔径试样需更大应力重分布区, 当W/D超过临界值3时, 有效材料尺寸不足, 导致名义强度骤降。综上, MI-SiC_f/SiC复合材料具备最优开孔拉伸性能的孔径为3 mm, 建议对W/D<3的开口结构采取补强措施。

关键词: MI-SiC_f/SiC复合材料, 开孔拉伸, 孔径效应, 数字图像相关, 声发射

Abstract:

To meet the design requirements for perforated structures in aero-engine hot-section components made of MI-SiC_f/SiC composites, this study prepared unnotched specimens and five types of open-hole specimens with different diameters (D=1-9 mm), and conducted room-temperature tensile tests. By integrating digital image correlation and acoustic emission techniques, the full-field strain evolution and internal damage signals were monitored in real time, systematically elucidating the influence of hole diameter on damage initiation threshold and evolution behavior. A three-dimensional finite element model was established to analyze the competing mechanisms between material nonlinearity, stress concentration at the hole-edge, and stress interaction at the hole-edge. The results indicate that the open-hole tensile strength exhibits a nonlinear relationship with the hole diameter: when D≤3 mm, the strength increases slowly with increasing diameter, whereas it decreases sharply for D>3 mm. A critical threshold exists concerning the width-to-diameter ratio (W/D): specifically, when W/D<3, stress concentration interference between the hole and the specimen edge leads to a pronounced decline in load-bearing capacity, with geometric effects dominating the failure behavior. Moreover, damage initiation stress decreases with increasing hole diameter. Small-hole specimens (D≤3 mm) maintain a sequential damage evolution process, while large-hole specimens (D>3 mm) exhibit concurrent multiple damage modes. Finite element analysis reveals that the stress peak shifts away from the hole edge once the material enters the nonlinear stage, resulting in early failure in specimens with diameter of 1-2 mm due to the overlap between the high-stress zone and inherent material defects. Larger holes require a larger stress redistribution zone. When W/D exceeds the critical value of 3, the available material width becomes insufficient, ultimately leading to a sharp decrease in nominal tensile strength. In conclusion, the optimal open-hole tensile performance of MI-SiC_f/SiC composites is achieved at a hole diameter of 3 mm. Reinforcement designs are recommended for open-hole structures with W/D<3.

Key words: MI-SiC_f/SiC composite, open-hole tensile, hole diameter effect, digital image correlation, acoustic emission

中图分类号:

V231
TB332

王雅娜, 宋九鹏, 王海润, 李天山, 焦健. MI-SiC_f/SiC复合材料开孔拉伸性能孔径效应研究[J]. 无机材料学报, 2026, 41(5): 653-662.

WANG Yana, SONG Jiupeng, WANG Hairun, LI Tianshan, JIAO Jian. Hole Diameter Effect on Open-hole Tensile Mechanical Property of MI-SiC_f/SiC Composites[J]. Journal of Inorganic Materials, 2026, 41(5): 653-662.

图/表 19

图1 试验件构型、尺寸与试样加载图

Fig. 1 Test specimen configuration, dimensions and photograph of the loading setup (a) Open-hole tensile specimen; (b) Unnotched tensile specimen; (c) Photograph of the specimen under loading. Unit: mm

图2 开孔拉伸试验件孔边应力分布规律示意图

Fig. 2 Schematic diagram of stress distribution characteristics around the hole in an open-hole tensile specimen

表1 试样几何构型和理论应力集中系数

Table 1 Specimen geometry and theoretical stress concentration factor

Specimen	D/mm	W/D	K_t
K0	0	/	/
K1	1	18	2.844
K2	2	9	2.707
K3	3	6	2.582
K4	6	3	2.302
K5	9	2	2.130

图3 无孔与开孔试样的拉伸曲线和断口形貌对比

Fig. 3 Comparison of tensile curves and fracture surface morphologies between unnotched and open-hole specimens (a) Nominal open-hole tensile stress-strain curves; (b) Net-section stress-strain curves; (c) Fracture morphologies of OHT specimens

表2 不同孔径试样的拉伸刚度和强度

Table 2 Tensile stiffness and strength for specimens with different hole diameters

Specimen	D/ mm	E_OHT/ GPa	E_NS/ GPa	S_OHT/ MPa	S_NS/ MPa	σ_{p_OHT}/ MPa	σ_{p_NS}/ MPa	σ_peak/ MPa
K0	0	206	206	228	228	125	125	125
K1	1	200	212	155	164	106	112	301
K2	2	203	229	158	177	98.8	111	267
K3	3	204	245	162	194	98.1	117	253
K4	6	186	278	120	179	90.0	134	207
K5	9	83.2	164	47.3	93.1	20.5	40.5	43.7

图4 孔径对试样(a)拉伸强度和(b)模量参数的影响

Fig. 4 Effect of hole diameter on (a) tensile strength properties and (b) module properties of specimens

图5 无孔试样的(a)峰值频率曲线和(b)归一化累积能量曲线

Fig. 5 (a) Peak frequency and (b) normalized cumulative energy curves of unnotched specimen

图6 开孔试样的(a)有限元模型及其(b)载荷边界条件

Fig. 6 (a) Finite element model of the open-hole specimen and (b) corresponding applied loads and boundary conditions

图7 K1~K5试样孔边应力预测结果

Fig. 7 Stress predictions around holes in K1-K5 specimens (a) Elastic model results; (b) Nonlinear model results; (c) Stress distribution along hole edge to the specimen edge line

表3 不同孔径试样的特征尺寸分析结果

Table 3 Characteristic dimension analysis for specimens with different hole diameters

Specimen	D/mm	L_e/mm	L_p/mm
K1	1	0.159	0.225
K2	2	0.337	0.505
K3	3	0.559	0.781
K4	6	0.584	/
K5	9	/	/

图S1 不同孔径下的试验件内部缺陷的CT重构图像

Fig. S1 CT reconstructed images of internal defects in specimens with different hole diameters (a) K1 specimen; (b) K2 specimen; (c) K3 specimen; (d) K4 specimen; (e) K5 specimen

图S2 OHT试样K1的(a)峰值频率和(b)归一化累积能量曲线

Fig. S2 (a) Peak frequency and (b) normalized cumulative energy curves of K1 OHT specimen

图S3 OHT 试样K2的(a)峰值频率曲线和(b)归一化累积能量

Fig. S3 (a) Peak frequency and (b) normalized cumulative energy curves of K2 OHT specimen

图S4 K3试验件的(a)峰值频率曲线和(b)归一化累积能量

Fig. S4 (a) Peak frequency and (b) normalized cumulative energy curves of K3 specimen

图S5 K4试验件的(a)峰值频率曲线和归一化累积能量

Fig. S5 (a) Peak frequency and (b) normalized cumulative energy curves of K4 specimen

图S6 K5试验件的(a)峰值频率曲线和(b)归一化累积能量曲线

Fig. S6 (a) Peak frequency and (b) normalized cumulative energy curves of K5 specimen

图S7 孔边到试样边缘连线上的应变分布

Fig. S7 Longitudinal tensile strain distribution along the hole-to-side line (a) K1 specimen; (b) K2 specimen; (c) K3 specimen; (d) K4 specimen; (e) K5 specimen

表S1 5种不同孔径试样不同应力水平下表面应变场的整体变化规律

Table S1 Variation of the full-field surface strain at different stress levels for specimens with five different hole diameters

	σ_OHT/MPa	46	82	113	138	149	155
K1
K2	σ_OHT/MPa	23.5	84.0	112	144	155	158
K2
K3	σ_OHT/MPa	34.1	78.0	108	142	155	162
K3
K4	σ_OHT/MPa	29.1	43.0	85.2	107	120	103
K4
K5	σ_OHT/MPa	15.1	28.0	36.1	47.2	46.0	37.1
K5

表S2 声发射信号特征点应力下的DIC应变云图

Table S2 DIC strain contour map of the stress corresponding to acoustic emission signal feature points

Specimen	First occurrence of acoustic emission signals on the peak frequency curve	First occurrence of an energy jump on the normalized cumulative energy curve	Peak frequency reaches the first peak point
K1	σ_OHT=32.2 MPa	σ_OHT=52.7 MPa	σ_OHT=102 MPa
K2	σ_OHT=23.1 MPa	σ_OHT=37.4 MPa	σ_OHT=121 MPa
K3	σ_OHT=27.0 MPa	σ_OHT=36.6 MPa	σ_OHT=104 MPa
K4	σ_OHT=16.9 MPa	σ_OHT=29.5 MPa	σ_OHT=44.1 MPa
K5	σ_OHT=14.4 MPa	σ_OHT=16.2 MPa	σ_OHT=47.4 MPa

参考文献 23

[1]	李龙彪. 陶瓷基复合材料在航空发动机应用与适航符合性验证研究进展. 复合材料学报, 2025, 42(1): 54.
[2]	焦健, 孙世杰, 焦春荣, 等. SiC_f/SiC复合材料涡轮导向叶片研究进展. 复合材料学报, 2023, 40(8): 4342.
[3]	王雅娜, 李天山, 王海润, 等. GE公司预浸料-熔渗工艺SiC_f/SiC复合材料应用研究历程及启示. 航空材料学报, 2025, 45(2): 1. DOI
[4]	刘虎, 束小文, 洪智亮, 等. 航空发动机用SiC/SiC复合材料典型元件设计及性能评价研究进展. 材料导报, 2023, 37(14): 12.
[5]	ASTM International. Standard test method for open-hole tensile strength of fiber-reinforced advanced ceramic composites: ASTM C1869-18. West Conshohocken: ASTM International, 2023.
[6]	KALLURI S, VERRILLI M J. Influence of holes on the in-plane tensile strength and fatigue durability of a Nicalon™/Si-N-C ceramic matrix composite. Ceramic Engineering and Science Proceedings, 2003, 24(4): 427.
[7]	HAQUE A, AHMED L, RAMASETTY A. Stress concentrations and notch sensitivity in woven ceramic matrix composites containing a circular hole—an experimental, analytical, and finite element study. Journal of the American Ceramic Society, 2005, 88(8): 2195. DOI URL
[8]	GYEKENYESI A L, MORSCHER G N. Damage progression and stress redistribution in notched SiC/SiC composites. Journal of Materials Engineering and Performance, 2010, 19(9): 1298. DOI URL
[9]	GYEKENYESI A L, MORSCHER G N. Evaluating the mechanical behavior of notched SiC/SiC composites using thermoelastic stress analysis. Proceedings of SPIE, Bellingham, 2004: 456-465.
[10]	MORSCHER G N, GYEKENYESI J Z, GYEKENYESI A L. Mechanical behavior of notched SiC/SiC composites. ASME International Gas Turbine and Aeroengine Congress, New Orleans, 2001: 1-7.
[11]	RUGGLES-WRENN M B, KURTZ G. Notch sensitivity of fatigue behavior of a Hi-Nicalon™/SiC-B₄C composite at 1,200 ℃ in air and in steam. Applied Composite Materials, 2013, 20: 891. DOI URL
[12]	GOWAYED Y, OJARD G, CHEN J, et al. Accumulation of time-dependent strain during dwell-fatigue experiments of iBN- Sylramic melt infiltrated SiC/SiC composites with and without holes. Composites Part A: Applied Science and Manufacturing, 2011, 42(12): 2020. DOI URL
[13]	MCNULTY J C, HE M Y, ZOK F W. Notch sensitivity of fatigue life in a Sylramic™/SiC composite at elevated temperature. Composites Science and Technology, 2001, 61(9): 1331. DOI URL
[14]	SANTHOSH U, AHMAD J, JOHN R, et al. Modeling of stress concentration in ceramic matrix composites. Composites Part B: Engineering, 2013, 45: 1156. DOI URL
[15]	GUAN X Y, WANG Y N, JIAO J, et al. Hierarchical modeling of strain-concentrating effect in notched ceramic-matrix composite laminates. International Journal of Mechanical Sciences, 2025, 304: 110641. DOI URL
[16]	LIU H, LI L B, WANG Y N, et al. In situ damage propagation and fracture in notched cross-ply SiC/SiC composites: experiment and numerical modeling. Journal of the European Ceramic Society, 2024, 44(4): 2052. DOI URL
[17]	刘海龙. SiC/SiC陶瓷基复合材料力学性能与失效机理研究. 上海: 上海交通大学硕士学位论文, 2020.
[18]	PETERSON R E, PLUNKETT R. Stress concentration factors. Naval Engineers Journal, 2010, 67(3): 697.
[19]	MORSCHER G N. Stress-dependent matrix cracking in 2D woven SiC-fiber reinforced melt-infiltrated SiC matrix composites. Composites Science and Technology, 2004, 64(9): 1311. DOI URL
[20]	MORSCHER G N, MAXWELL R. Monitoring tensile fatigue crack growth and fiber failure around a notch in laminate SiC/SiC composites utilizing acoustic emission, electrical resistance, and digital image correlation. Journal of the European Ceramic Society, 2019, 39(2/3): 229. DOI URL
[21]	BACHE M R, NEWTON C D, JONES J P, et al. Advances in damage monitoring techniques for the detection of failure in SiC_f/SiC ceramic matrix composites. Ceramics, 2019, 2(2): 347. DOI URL
[22]	DASSIOS K G, AGGELIS D G, KORDATOS E Z, et al. Cyclic loading of a SiC-fiber reinforced ceramic matrix composite reveals damage mechanisms and thermal residual stress state. Composites Part A: Applied Science and Manufacturing, 2013, 44: 105. DOI URL
[23]	MORSCHER G N, FERGUSON C, PRATT S, et al. Acoustic emission accuracy from a tensile test of a ceramic matrix composite. Journal of the American Ceramic Society, 2024, 107(12): 8556. DOI URL