共查询到20条相似文献，搜索用时 156 毫秒
1.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｎａｔｕｒｅｏｆｓｕｂｓｔｒａｔｅｓｈａｓａｃｒｕｃｉａｌｅｆｆｅｃｔｏｎｂｏｔｈｔｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆｔｈｅｆｉｌｍｓａｎｄｔｈｅｇｒｏｗｔｈｍｅｃｈａｎｉｓｍ (Ｈａｕｓｅｔａｌ.,1 987;Ｋｒｕｇｅｔａｌ.,1 990 ) .Ｆｏｒｉｎｓｔａｎｃｅ,ｔｈｅｔｏｐｓｕｒｆａｃｅｓｏｆｍｅｔａｌｌｉｃｔｈｉｎｆｉｌｍｓｄｅｐｏｓｉｔｅｄｏｎｓｏｌｉｄｓｕｂｓｔｒａｔｅｓｇｅｎｅｒａｌｌｙｈａｖｅａｒｏｕｇｈｓｔｒｕｃｔｕｒｅ ,ｗｈｉｃｈｃａｎｂｅｄｅｓｃｒｉｂｅｄｂ… 相似文献
2.
《上海大学学报(英文版)》2000,(4)
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｌｏｎｇｒａｎｇｅｏｒｄｅｒｅｄｉｎｔｅｒｍｅｔａｌｌｉｃｓｐｏｓｓｅｓｓａｎｕｍｂｅｒｏｆａｄｖａｎｔａｇｅｓ ,ｓｕｃｈａｓｌｏｗｄｅｎｓｉｔｙ ,ｇｏｏｄｈｉｇｈ ｔｅｍ ｐｅｒａｔｕｒｅｓｔｒｅｎｇｔｈ ,ｅｘｃｅｌｌｅｎｔｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅ ,ｗｈｉｃｈｍａｋｅｉｔｐｏｓｓｉｂｌｅｆｏｒｔｈｅｍｔｏｂｅｕｓｅｄａｓｓｔｒｕｃ ｔｕｒａｌｍａｔｅｒｉａｌｓｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅａｐｐｌｉｃａｔｉｏｎｓ .Ｈｏｗｅｖｅｒ ,ｍｏｓｔｏｆｔｈｅ… 相似文献
3.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｔｒｕｃｔｕｒｅｏｆｌａｂｏｒｉｎｔｈｅｅｃｏｎｏｍｉｃｓｏｃｉ ｅｔｙｉｓａｋｅｙｉｎｄｉｃａｔｉｏｎｏｆｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅｎａｔｉｏｎ ;ａｎｄｂａｓｅｄｏｎｔｈｅｓｉｔｕａｔｉｏｎｏｆＣｈｉｎａ ,ｒｅ ｌａｔｅｓｔｏｔｈｅｍｉｇｒａｔｉｏｎｏｆｉｔｓｈｕｇｅｓｕｒｐｌｕｓａｇｒｉｃｕｌ ｔｕｒａｌｌａｂｏｒ,ｗｈｉｃｈ ,ｂａｓｅｄｏｎａ 1 998ｅｓｔｉｍａｔｅ ,ａｃｃｏｕｎｔｅｄｆｏｒａｔｌｅａｓｔ2 6%ｏｆｉｔｓ4 50ｍｉｌｌｉｏｎｒｕ ｒａｌｌａ… 相似文献
4.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｇｅｎｅｒａｔｉｎｇｌｏｃａｌｉｚｅｄｃｏｈｅｒｅｎｔｓｔｒｕｃｔｕｒｅｓｏｆｔｈｅ (2 +1) ｄｉｍｅｎｓｉｏｎａｌｎｏｎｌｉｎｅａｒｅｖｏｌｕｔｉｏｎｅｑｕａｔｉｏｎｓｈａｓｃｏｎ ｔｉｎｕｅｄｔｏｂｅａｃｈａｌｌｅｎｇｉｎｇｃｏｎｔｅｍｐｏｒａｒｙｐｒｏｂｌｅｍａｆｔｅｒｔｈｅａｄｖｅｎｔｏｆｄｒｏｍｉｏｎｓｗｈｉｃｈａｒｅｅｘｐｏｎｅｎｔｉａｌｌｙｌｏｃａｌ ｉｚｅｄｓｔｒｕｃｔｕｒｅｓｄｒｉｖｅｎｂｙｓｏｍｅｓｔｒａｉｇｈｔｌｉｎｅｇｈｏｓｔｓｏｌｉ ｔｏｎｓｕ… 相似文献
5.
PENG Li ming MAO Xie min XU Kuang di 《上海大学学报(英文版)》1999,3(4):313-317
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｗｉｔｈｔｈｅｉｎｃｒｅａｓｅｏｆｒｅｑｕｉｒｅｍｅｎｔｓｆｏｒｍａｔｅｒｉａｌｐｒｏｐｅｒｔｉｅｓｉｎｉｎｄｕｓｔｒｙａｐｐｌｉｃａｔｉｏｎｓ,ｓｕｃｈｍａｔｅｒｉａｌｓｗｉｔｈａｎｉｓｏｔｒｏｐｉｃｍｉｃｒｏｓｔｒｕｃｔｕｒｅｓｇｅｔｅｘｐａｎｓｉｖｅａｐｐｌｉｃｏｔｉｏｎｉｎｉｎｄｕｓｔｒｙ［１,２］．Ｄｉｒｅｃｔｉｏｎａｌｓｏｌｉｄｉｆｉｃａｔｉｏｎｍｉｃｒｏｓｔｒｕｃｔｕｒｅｉｓｏｎｅｏｆｔｈｅｓｅｔｙｐｅｓｏｆｍａｔｅｒｉａｌｓ,ｗｈｉｃｈｉｎｃｌｕｄ… 相似文献
6.
ＮＴＲＯＤＵＣＴＩＯＮＴｅｍｐｅｒａｔｕｒｅｆｉｅｌｄｃｈａｎｇｅｗｉｌｌｐｒｏｄｕｃｅｔｈｅｒ ｍａｌｓｔｒｅｓｓｅｓｉｎｓｔｒｕｃｔｕｒｅｓ.Ｉｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｄｉｆｆｅｒｅｎｔｍａｔｅｒｉａｌｓｇｅｎｅｒａｔｅｄｉｆｆｅｒｅｎｔｓｔｒｅｓｓｒｅ ｓｐｏｎｓｅｓ ,ａｎｄｔｈａｔｉｎｓｏｍｅｃａｓｅｓ,ｔｈｅｒｍａｌｓｔｒｅｓｓ ｅｓａｒｅｌａｒｇｅｅｎｏｕｇｈｔｏｃａｕｓｅｓｔｒｕｃｔｕｒｅｆａｉｌｕｒｅ .Ｓｏｉｔｉｓｍｅａｎｉｎｇｆｕｌａｎｄｉｍｐｏｒｔａｎｔｔｏｓｔｕｄｙｄｙ… 相似文献
7.
ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｅｘｃａｖａｔｉｏｎ ,ｎｏｒｍａｌａｎａｌｙｓｉｓｉｓｎｏｔｇｏｏｄｅｎｏｕｇｈｔｏｍｅｅｔｅｎｇｉｎｅｅｒｉｎｇｎｅｅｄｓｄｕｅｔｏｔｈｅｕｎ ｃｅｒｔａｉｎｔｙｏｆｆｏｒｃｅｓａｐｐｌｉｅｄｏｎｂｒａｃｅｓｔｒｕｃｔｕｒｅｓ,ｓｏｉｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓ,ａｎｄｓｏｉｌｍｏｄｅｌｕｓｅｄ .Ｔｏｇｕａｒａｎｔｅｅｔｈａｔｔｈｅｃｏｎｓｔｒｕｃｔｉｏｎｐｒｏｃｅｓｓｃａｎｂｅｓｍｏｏｔｈｌｙｐｅｒｆｏｒｍｅｄ ,ｍｅａｓｕｒｅｍｅｎｔｓｉｎｓｉｔｕａｒｅｕｓｕａ… 相似文献
8.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆｔｈｉｎｆｉｌｍｓｐｌａｙｓａｃｒｕ ｃｉａｌｒｏｌｅｉｎａｗｉｄｅｖａｒｉｅｔｙｏｆｐｈｙｓｉｃａｌｐｒｏｃｅｓｓｅｓ.Ｔｈｅｒｅａｒｅｃｌｅａｒｅｖｉｄｅｎｃｅｓｔｈａｔｍａｎｙｐｈｙｓｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆａｔｈｉｎｆｉｌｍｖａｒｙｄｒａｍａｔｉｃａｌｌｙａｓｉｔｓｍｉｃｒｏｓｔｒｕｃｔｕｒｅｃｈａｎｇｅｓ (Ｈａｕｓｅｔａｌ.,1 987) .Ｆｏｒｉｎｓｔａｎｃｅ,ｒｏｕｇｈｓｕｂｓｔｒａｔｅｓｃａｎｂｅｕｓｅｄｔｏｆａｂｒｉｃ… 相似文献
9.
Shape optimization of plate with static and dynamic constraints via virtual laminated element 总被引：1，自引：0，他引：1
ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｓｔｒｕｃｔｕｒａｌｄｅｓｉｇｎ ,ｉｔｉｓｎｅｃｅｓｓａｒｙｔｏｆｉｎｄｔｈｅａｐｐｒｏｐｒｉａｔｅｃｏｎｆｉｇｕｒａｔｉｏｎｏｆａｓｔｒｕｃｔｕｒｅｓｕｂ ｊｅｃｔｅｄｔｏｇｉｖｅｎｌｏａｄｓ.Ｃｏｎｆｉｇｕｒａｔｉｏｎｏｆａｓｔｒｕｃ ｔｕｒｅｉｎｃｌｕｄｅｓｐａｒａｍｅｔｅｒｓｓｕｃｈａｓｉｔｓｄｉｍｅｎｓｉｏｎ ,ｉｔｓｓｈａｐｅ ,ｉｔｓｔｏｐｏｌｏｇｙａｎｄｓｏｏｎ .Ｔｈｅｏｂｊｅｃｔｏｆｏｐｔｉｍｉｚａｔｉｏｎｏｆｔｅｎｒｅｑｕｉｒｅｓｔｈａｔａｓｔｒｕｃｔｕ… 相似文献
10.
ＩＮＴＲＯＤＵＣＴＩＯＮＲｉｂｏｚｙｍｅｗａｓｆｉｒｓｔｄｅｓｃｒｉｂｅｄｂｙＣｅｃｈａｎｄＡｌｔｍａｎｉｎ 1 981 .ＴｈｉｓｆｏｒｍｏｆＲＮＡｈａｄｈｉｇｈｌｙｓｐｅｃｉｆｉｃｅｎｄｏｎｕｃｌｅａｓｅａｃｔｉｖｉｔｉｅｓｔｏＲＮＡ (Ｋｒｕｇｅｒｅｔａｌ.,1 982 ) .Ｒｉｂｏｚｙｍｅｓｈａｖｅｔｈｒｅｅｓｔｒｕｃｔｕｒｅｓ:ｈａｍｍｅｒｈｅａｄ ,ｈａｉｒｐｉｎａｎｄａｘｅｒｉｂｏｚｙｍｅｓ.Ａｍｏｎｇｔｈｅｍ ,ｔｈｅｈａｍｍｅｒｈｅａｄｒｉｂｏｚｙｍｅｈａｓａｓｉｍｐｌｅｒｓｅｃｏｎｄａｒｙｓｔｒｕｃ… 相似文献
11.
Based on the traditional theory of fracture, time-dependence of rock fracture is taken into account and the creep fracture
criteria are given. The effect of the microcrack zone on fracture toughness is analyzed. Finally, a model for time prediction
of rheological fracture is derived and its feasibility is proven.
Supported by the National Natural Science Foundation of China (59809005) and the Science Foundation of Shanghai Municipal
Commission of Science and Technology (96QF14009) 相似文献
12.
The mechanism and criterion of crack initiation and propagation of rocks were investigated by many researchers,And the creep behaviour of rocks was also theoretically and experimentally studied by some scientists and engineers.The characteristics of crack initation and propagation of rocks under creep condition.however,are very improtant for rock engineering and still not paid enough attention by researchers,In this paper,the criterion and mechanism of crack initiation and propagation under creep condition were investigated using specimens collected from sandstone rock formations outcropping in the Emei Mountain,the Sichuan Province of China.Cuboid specimens under three point bending were used in this investigation.All specimens were classified into four sorts and used for Mode-I fracutre of creep frcture tests.The experimental result shows that due to creep deformation.rock crack will inevitably initialt and propagate under a load of KI,which is less than fracture toughness KIC but not less than a constant(marked as KIC2),KIC2 indicates the ability of rock to resist crack initiation and propagation under creep conditions and is less than fracture tough ness KIC.defined as creep fracture toughness in this paper,KIC2 should be considered as an importnat parameter on design and computation of rock engineering.The microstructureal mechanism for crack initiation and propagation of rock materials under creep condition was introduced based on competitive model between softening effect and hardening effect,and the validity of test result was explained.The test result was also verified in rheological theory.When KI is more than KIC2 but less than KIC,rock crack will initiate and propagate after a time interval of sustained loading under creep condition.In order to find the relation between duration of sustained lading.which can lead to crack initiation and propagation,and the initial stress intensity factor KI,an unequal0interval time sequence forecasting and predicting model was introduced,and the relation was obtained for homogeneous and isotropic fine-grained red sandstone.Finally a modified fracture toughness formula was given,in which the influence of fracture process zone(FPZ) was fully considered. 相似文献
13.
采用反射式焦散线方法对水泥石中添加玻璃纤维后的强度变化问题进行了实验研究.首先,制作了不添加与添加玻璃纤维的2种水泥石试件,并采用镜面移植方法在试件的表面进行反射镜面的制作与加工.然后,采用多火花式高速摄影系统对试件在冲击断裂过程中的裂纹扩展和裂纹尖端焦散线的情景进行记录.最后,对2种试件的裂纹起裂时间、动态应力强度因子和裂纹扩展速度等参数进行计算和对比分析.分析发现,玻璃纤维提高了水泥石的断裂韧度、延迟了裂纹的起裂时间,对水泥石具有明显的强化效应.实验结果对研究水泥石的断裂力学属性特征具有一定意义. 相似文献
14.
Fatigue and fracture behavior of nickel-based superalloy Inconel 718 up to the very high cycle regime 总被引：2，自引：0，他引：2
Xian-feng Ma Zheng Duan Hui-ji Shi Ryosuke Murai Eiichi Yanagisawa 《浙江大学学报(A卷英文版)》2010,11(10):727-737
The fatigue and fracture behavior of nickel-based superalloy Inconel 718 was investigated up to the very high cycle regime under rotary bending tests at room temperature. It was found that this superalloy can still fracture after exceeding 107 cycles. Fractographic analysis revealed that there was a transition from fatigue crack initiation at multi-sites to single initiation with decreasing stress levels. The fracture surface can be divided into four areas according to the appearance, associated with fracture mechanics analysis of the corresponding stress intensity factors. The fracture mechanism dominant in each area was disclosed by scanning electron microscope examination and analyzed in comparison with those obtained from the crack growth tests. Subsequently, life prediction modeling was proposed by estimating the crack initiation and propagation stage respectively. It was found that Chan （2003）＇s model for initiation life and the Paris law for growth life can provide comparable predictions against the experimental life. 相似文献
15.
A first order system model of fracture healing 总被引：1，自引：0，他引：1
INTRODUCTION Fracture healing is an important research subject in biomechanics. During the last years, many theories and simulation models have been proposed for de- veloping a comprehensive view of the mechanisms controlling bone morphogenesis. Pauwels (1960) was one of the first authors to propose a theory of tissue differentiation in response to local mechanical stress and strain. He assumed that deviatoric stresses com- prise the specific stimulus for the formation of fibrous connecti… 相似文献
16.
A first order system model is proposed for simulating the influence of stress stimulation on fracture strength during fracture
healing. To validate the model, the diaphyses of bilateral tibiae in 70 New Zealand rabbits were osteotomized and fixed with
rigid plates and stress-relaxation plates, respectively. Stress shielding rate and ultimate bending strength of the healing
bone were measured at 2 to 48 weeks postoperatively. Ratios of stress stimulation and fracture strength of the healing bone
to those of intact bone were taken as the system input and output. The assumed first order system model can approximate the
experimental data on fracture strength from the input of stress stimulation over time, both for the rigid plate group and
the stress-relaxation plate group, with different system parameters of time constant and gain. The fitting curve indicates
that the effect of mechanical stimulus occurs mainly in late stages of healing. First order system can model the stress adaptation
process of fracture healing. This approach presents a simple bio-mathematical model of the relationship between stress stimulation
and fracture strength, and has the potential to optimize planning of functional exercises and conduct parametric studies.
Project (No. 39470698) supported by the National Natural Science Foundation of China 相似文献
17.
文章应用几种不同时间序列预测方法对中小企业销售额进行建模并预测,旨在建立适用于中小企业的预测方法和预测模型,收集了某企业某产品2006~2012年各月销售额数据,利用时间序列中的回归模型、ARIMA模型对其进行拟合建模,并运用各模型对2013年前6个月的销售额进行了预测及比较分析,从中选出预测精度相对较高的模型。 相似文献
18.
XING Yu-zhong FAN Tai-liang ZHENG Li-hui 《浙江大学学报(A卷英文版)》2006,7(11):1904-1910
INTRODUCTION Several fields in Liaohe Basin are host to frac- tured hydrocarbon oil reservoir, fractures are consid- ered to influence productivity significantly in these reservoirs, which not only form a large part of the overall porosity, but also are responsible for the po- tential reservoir volume. More importantly, the frac- ture system facilitates permeability and flow. Ce- mented and closed fractures act as barriers to flow, whereas open fractures intersected by the wellbore may in… 相似文献
19.
目的:比较髌骨骨折患者行关节镜下改良张力带固定及切开复位内固定术对机体体温的影响。方法:将120例新鲜髌骨骨折患者随机分为关节镜下改良张力带固定组60例,切开复位内固定组60例,记录术晨、术毕、术后1~3 d晨监测的体温。结果:体温升高从术毕至术后3 d,关节镜组小于切开复位组(p<0.05)。结论:从术后体温恢复角度上看,治疗髌骨骨折患者关节镜下改良张力带固定优于切开复位内固定。 相似文献
20.
By using semisolid joining technique,the bonding of stainless steel and semisolid aluminum alloy is successfully realized.The relationships between interracial shear strength and solid fraction of aluminum alloy,bonding pressure and time of keeping pressure were studied by the method of orthogonal experiment.The interfacial structure and the fracture structure of the bonding plate are studied by means of optical microscope (OM) and scanning electron microscope (SEM).The results show that there is the best solid fraction between the solid phase line and the liquid phase line of the semisolid aluminum alloy,with the increase of bonding pressure and pressure time,the interfacial shear strength increases rapidly,and then with further increase of bonding pressure and pressure time,the shear strength rises little.Along the interface,solid phase and liquid phase bond with stainless steel by turns because of the different diffusion ability.So,a new type of non-equilibrium diffusion interfacial structure is constructed at the interface of stainless steel and aluminum alloy,compound mechanism of plastic and brittle fracture interface was formed at the shear fracture interface. 相似文献