火箭推进

针对刻痕膜片结构的断裂问题,提出了一种适合拉剪混合断裂模式修正的(Gurson-Tvergaard-Needleman,GTN)模型,在屈服势中使用孔洞体积分数和剪切损伤变量分别表征拉伸和剪切损伤机制引起的材料刚度下降及失效过程,建立了两个损伤参数率形式的累积方程。基于ABAQUS的用户子程序开发出双损伤变量GTN损伤材料本构,对刻痕膜片的破裂过程进行计算分析,得到了破裂压力的精确计算值。借助于软件的失效单元删除功能,模拟出了裂纹在刻痕膜片中的萌生、扩展以及最终断裂过程。与试验结果的对照表明,模型能够准确模拟出刻痕膜片的破裂压力及断裂过程,可广泛用于模拟拉剪混合载荷模式下的韧性金属断裂过程。

A new modification to Gurson-Tvergaard-Needleman(GTN)model was proposed for the simulation of ductile fracture behaviors under combined tensile and shear loading mode in pre-notched metal diaphragm.Two distinctive damage parameters,respectively related to tensile and shear damage mechanisms were introduced into yield function as internal variables of material degradation process.The evolution laws of the two damage parameters were given in rate-form.The damage constitutive model was implemented into the commercial codes ABAQUS via user defined material subroutines and applied to simulate the ductile fracture of the pre-cracked metal diaphragm to acquire the exact bursting pressure.The process of crack initiation,propagation and final fracture in the diaphragm was also reasonably predicted by the element removal procedure of ABAQUS/Explicit.The comparison with the experimental results shows that the proposed model can accurately simulate the fracture pressure and fracyure process of the notched diaphragm,and can be windely used to simulate the fracture process of ductile metals under tension shear mixed load mode.

引言
1 刻痕膜片及气动破裂试验
2 修正的 GTN 模型
3 刻痕膜片断裂过程计算分析
4 结论

图1 剩余厚度测量位置及截取方法<br/>Fig.1 Residual thickness and determination method

图1 剩余厚度测量位置及截取方法
Fig.1 Residual thickness and determination method

表1 刻痕膜片剩余厚度测量结果<br/>Tab.1 Residual thickness of the pre-notched diaphragm 单位:μm

表1 刻痕膜片剩余厚度测量结果
Tab.1 Residual thickness of the pre-notched diaphragm 单位:μm

$图2 刻痕膜片、膜片阀及气动试后破裂形貌<br/>Fig.2 Pre-notched diaphragm、membrane valve and fracture surface after burst testing$

图2 刻痕膜片、膜片阀及气动试后破裂形貌
Fig.2 Pre-notched diaphragm、membrane valve and fracture surface after burst testing

图3 刻痕膜片破裂压力试验及理论估算值<br/>Fig.3 The busting pressure of the pre-notched diaphragm by testing and calculation

图3 刻痕膜片破裂压力试验及理论估算值
Fig.3 The busting pressure of the pre-notched diaphragm by testing and calculation

图4 修正的GTN模型的屈服面<br/>Fig.4 Yield surface of the modified GTN model

图4 修正的GTN模型的屈服面
Fig.4 Yield surface of the modified GTN model

图5 刻痕膜片有限元模型<br/>Fig.5 The FEM model of pre-notched diaphragm

图5 刻痕膜片有限元模型
Fig.5 The FEM model of pre-notched diaphragm

表2 TAD—M带材力学性能及损伤模型参数<br/>Tab.2 The macro-mechanical properties and damage model parameters for TAD—M

表2 TAD—M带材力学性能及损伤模型参数
Tab.2 The macro-mechanical properties and damage model parameters for TAD—M

图6 刻痕膜片破裂压力计算值<br/>Fig.6 The predicted bursting pressure by two-damage-parameter GTN model

图6 刻痕膜片破裂压力计算值
Fig.6 The predicted bursting pressure by two-damage-parameter GTN model

$图7 刻痕膜片断裂过程计算结果<br/>Fig.7 The simulated fracture process of pre-notched diaphragm by two-damage-parameter GTN model$

图7 刻痕膜片断裂过程计算结果
Fig.7 The simulated fracture process of pre-notched diaphragm by two-damage-parameter GTN model

[1] 白少卿,孙亮.膜片阀破裂压力稳定性研究[J].火箭推进,2015,41(6):46-50. BAI S Q,SUN L.Research of bursting pressure stability for membrane valve[J].Journal of Rocket Propulsion,2015,41(6):46-50.
[2] 宁建华.光刻膜片在膜片阀中的应用[J].火箭推进,2005,31(1):33-34. NING J H.Photoetching diaphragm in burst valve application[J].Journal of Rocket Propulsion,2005,31(1):33-34.
[3] 王伟,李江,王春光,等.隔舱式双脉冲发动机金属膜片设计与实验研究[J].推进技术,2013,34(8):1115-1120.
[4] 王春光,任全彬,田维平,等.脉冲发动机中金属膜片式隔舱动态破坏过程研究[J].固体火箭技术,2013,36(1):22-26.
[5] 姜薇.基于细观损伤机理的韧性断裂研究[D].西安:西北工业大学,2016.
[6] JIANG W,LI Y Z,SU J.Modified GTN model for a broad range of stress states and application to ductile fracture[J].European Journal of Mechanics-A/Solids,2016,57:132-148.
[7] BARSOUM I,FALESKOG J.Rupture mechanisms in combinedtension and shear—Micromechanics[J].International Journal of Solids and Structures,2007,44(17):5481-5498.
[8] GAO X S,ZHANG G H,ROE C.A study on the effect of the stress state on ductile fracture[J].International Journal of Damage Mechanics,2010,19(1):75-94.
[9] BENZERGA A A,LEBLOND J B.Ductile fracture by void growth to coalescence[J].Advances in Applied Mechanics,2010,44:169-305.
[10] DANAS K.Influence of the Lode parameter and the stress triaxiality on the failure of elasto-plastic porous materials[J].International Journal of Solids and Structures,2012,49(11/12):1325-1342.
[11] PARDOEN T,HUTCHINSON J W.An extended model for void growth and coalescence[J].Journal of the Mechanics and Physics of Solids,2000,48(12):2467-2512.
[12] GURSONA L.Continuum theory of ductile rupture by void nucleation and growth:part I—yield criteria and flow rules for porous ductile media[J].Journal of Engineering Materials and Technology,1977,99(1):2-15.
[13] TVERGAARD V,NEEDLEMAN A.Analysis of the cup-cone fracture in a round tensile bar[J].Acta Metallurgica,1984,32(1):157-169.
[14] KOPLIK J,NEEDLEMAN A.Void growth and coalescence in porous plastic solids[J].International Journal of Solids and Structures,1988,24(8):835-853.
[15] 姜薇,李亚智,刘敬喜,等.基于微孔洞细观损伤模型的金属剪切失效分析[J].华中科技大学学报(自然科学版),2015,43(1):24-29.
[16] DUNAND M,MOHR D.On the predictive capabilities of the shear modified Gurson and the modified Mohr-Coulomb fracture models over a wide range of stress triaxialities and Lode angles[J].Journal of the Mechanics and Physics of Solids,2011,59(7):1374-1394.
[17] JACKIEWICZ J.Use of a modified Gurson model approach for the simulation of ductile fracture by growth and coalescence of microvoids under low,medium and high stress triaxiality loadings[J].Engineering Fracture Mechanics,2011,78(3):487-502.
[18] JEAN L.A continuous damage mechanics model for ductile fracture[J].Journal of Engineering Materials and Technology,1985,107(1):83-89.
[19] CHU C C,NEEDLEMAN A.Void nucleation effects in biaxially stretched sheets[J].Journal of Engineering Materials and Technology,1980,102(3):249-256.

备注

引言

1 刻痕膜片及气动破裂试验

2 修正的 GTN 模型

3 刻痕膜片断裂过程计算分析

4 结论

期刊信息