Loading...
Toggle navigation
Home
About
About Journal
Historical
Editorial Board
Subscription
Journal
Current Issue
Featured Article
Just Accepted
Archive
Mechanics Competition
全国周培源大学生力学竞赛
全国深空轨道设计竞赛
海峡两岸力学交流暨中学生力学夏令营
中学生趣味力学制作邀请赛
Download
Contact Us
Advertisement
Fund
中文
Journals of CSTAM
力学学报
Acta Mechanica Sinica
力学与实践
力学进展
Theo.& Appl.Mech.Letters
固体力学学报
Acta Mech.Solida.Sin
爆炸与冲击
计算力学
实验力学
工程力学
动力学与控制
岩土工程学报
力学季刊
地震工程与工程振动
世界地震工程
等离子体科学和技术
More
Author Center
Author's Guide
Author's Login
Review Login
Review's Guide
Peer Review Login
Editorial
Editor Work
Office Work
Reader Center
Reader's Guide
Subscription
IPAD Mobile Reading Platform
Member of CSTAM
User Name:
Pass Word:
Dynamics
More>>
Academic Activity Program
Table of Content
10 April 2009, Volume 31 Issue 2
Previous Issue
Next Issue
Education Study
Discussion of Serval Issues for Pure Beam Deflection Curve by Metheds of Graph Multiplication and Double Integral
2009, 31(2): 8283. DOI:
10.6052/100009922007030
Asbtract
(
1416
)
PDF
(258KB) (
613
)
Related Articles

Metrics
The accuracy key to the deflection curve of a uniform section straight beam subjected to the moment is a circle,however,the answers are both parabolas by metheds of graph multiplication and double integral .The reasons are analysed,and the error is given with a parabola replacing a circle.
Application study
MIXED MODE DYNAMIC STRESS INTENSITY FACTORS OF CRACKED STRAIGHT THROUGH FLATTENED BRAZILIAN DISC SPECIMENS
2009, 31(2): 4045. DOI:
10.6052/100009922007382
Asbtract
(
1649
)
PDF
(1060KB) (
639
)
Related Articles

Metrics
In order to establish a standard for the test of mixed mode dynamic fracture of rock with the cracked straight through flattened Brazilian disc (CSTFBD) specimen, we use finite element method first to check the related results in literature on the cracked straight through Brazilian disc specimen (CSTBD). The III mixed mode dynamic stress intensity factors (SIFs) of the two kinds of discs with different dimensionless crack lengths (i.e. the half length of the crack normalized by the radius of the specimen) are obtained to show that the differences of the dynamic SIF's time history between these two kinds of specimens are within 10{\%}, and the numerical method used in this paper is valid. Then for CSTFBD specimens, the III mixed ratio, the angle of crack initiation, and the loading angle for pure mode II fracture test are obtained. The results are useful for mixed mode dynamic fracture test of CSTFBD, including specimens preparation, the location and directional alignment of the strain gages, as well as the estimation for the crack initiation time and the crack initiation direction.
Education Study
A Discussion on One Section of Simplified Textbook of Elasticity
2009, 31(2): 9293. DOI:
10.6052/100009922007447
Asbtract
(
1177
)
PDF
(314KB) (
642
)
Related Articles

Metrics
Application study
INFLUENCE OF THE VOID DISTRIBUTION ON MACRORESPONSES OF FUNCTIONALLY GRADED PLATES
2009, 31(2): 5559. DOI:
10.6052/100009922007503
Asbtract
(
1247
)
PDF
(900KB) (
579
)
Related Articles

Metrics
Complex microstructures of functionally graded materials and their geometry make related strucutres more complex than plates, cylindrical shells and spherical shells. Therefore, the analytic solution of functionally graded structure is difficult to obtain, and the approximate solution and other calculation methods are used frequently. A new microelement method for the analysis of functionally graded structures is suggested to establish a quantitative relation between the macrocharacteristics and microstructures of functionally graded materials, and different combinations of materials for different macrocharacteristics can be found. By this microelement method, the influence of voids on the macroresponses can be analyzed. The threedimensional distributions of mechanical quantities of the functionally graded plates with different distributions, forms and positions of the voids are given, a transscale analysis between microconstitution and macroresponse of the functionally graded materials and structures can be carried out.
A NEW THEORETICAL MODEL FOR ARMORPIERCING MECHANICS
2009, 31(2): 2226. DOI:
10.6052/100009922007511
Asbtract
(
1334
)
PDF
(809KB) (
813
)
Related Articles

Metrics
Penetration mechanics is important both as a science and in practice of military engineering. For a quasisteady penetration of long rod projectile into semiinfinite thick target, a simplified model is developed, where the bullet incorporated mushroom head consists of unbroken zone, crush zone and hole dilating zone, and the target consists of hole dilating zone, crush zone and unbroken zone, with the strain rate effect being considered. A set of ODE is obtained through conservation laws of every part. Through theoretical analysis and calculation, the influences of the crush strain rate, crash strength of the projectile and the strain rate effect of the crash strength of the target on penetration depth are analyzed. The excellent agreement of the calculation results and the experiment shows the effectiveness of the simplified model.
Education Study
The analysis of section relative displacement in antisymmetric statically indeterminate frame without external restrctions
2009, 31(2): 7879. DOI:
10.6052/100009922007531
Asbtract
(
1137
)
PDF
(350KB) (
568
)
Related Articles

Metrics
On the basis of the principle of virtual work, the building of unitload state, when solving section relative displacement in antisymmetric statically indeterminate frame without external restrctions, is analyzed principally. The essential of the unitload method can be understood well by students from the analysis of this paper.
Application study
NUMERICAL SIMULATION OF INFLUENCE OF THE INNER STRUCTURE OF ULTRASONIC NOZZLES ON THE CHARACTERISTICS OF THE AIR MILLER
2009, 31(2): 1721. DOI:
10.6052/100008792007592
Asbtract
(
1124
)
PDF
(1144KB) (
846
)
Related Articles

Metrics
The structure and parameters of the nozzle of a jet mill device are optimized, numerical simulations of the inner structure are carried out with hydrokinetics software, the stress analysis of the structure is conducted with finite element software, and the effects of inlet diameter, section area of throat region, passage shape and diffusion angle on supersonic nozzle are analyzed. Optimized operation parameters include pressure of 3.5\,MPa and inlet diameter of 6\,mm after comparing different simulations. In the range of $8^\circ \sim 12^\circ$, the diffusion angle has little effect on the performance of the designed supersonic nozzle.
Review
ADVANCES IN HYPERVELOCITY IMPACT DYNAMICS AND SPACECRAFT PROTECTION RESEARCH
Yiyong LI Huairong SHEN Zhi LI
2009, 31(2): 1116. DOI:
10.6052/100008792008017
Asbtract
(
1307
)
PDF
(1272KB) (
749
)
Related Articles

Metrics
Hypervelocity impact dynamics and spacecraft protection as an important part of hypervelocity impact technology, is reviewed in this paper. Its research background is outlined. Its research progress covers the following five aspects: making hole in the thick board, penetration in the critical thick board, forming debris cloud from the thin board, experimental simulation technique and numerical simulation technique. The damage effect of hypervelocity impact spacecraft is analyzed. The spacecraft protection requirements are given, and the project design and performance of the spacecraft protection structure are discussed.
Application study
WIND LOADS ON MULTI NATURAL DRAFT COOLING TOWERS IN A POWER PLANT
Li Yinan
2009, 31(2): 6568. DOI:
10.6052/100008792008018
Asbtract
(
1308
)
PDF
(851KB) (
672
)
Related Articles

Metrics
Natural draft cooling tower is a highrise thin shell structure. The displacement in the top of the cooling tower can be tens of centimeters under wind loads, several times of the wall thickness. Cooling tower is very sensitive to wind loads, especially in multitowers conditions, where the wind velocity, wind pressure distribution and airflow among towers are quite complex. On the basis of the experiment results on irregular multitowers, this paper put forward some proposals about determining wind loads of natural draft cooling tower in multi towers conditions.
ESTIMATING THRESHOLDS OF DAMAGES BASED ON NATURAL FREQUENCY METHOD
2009, 31(2): 5054. DOI:
10.6052/100008792008023
Asbtract
(
1243
)
PDF
(938KB) (
784
)
Related Articles

Metrics
The damage thresholds obtained by natural frequency method can be used as a criterion to justify the usefulness of practical engineering structure. The natural frequency method consists of analyzing the influential factors of the damage, and a cantilever beam model is taken as an example. Both numerical and theoretical results indicate that, if the frequency measurement error is known, this method can be used to estimate the thresholds, during the early period of damage. The thresholds obtained by this method agree with the numerical results very well.
DESIGN OF PARTIAL SIMILARITY MODELS AND THEIR EVALUATION METHOD IN WATER FLOODING PHYSICAL SIMULATION
Bai YuHu
2009, 31(2): 2730. DOI:
10.6052/100008792008034
Asbtract
(
1175
)
PDF
(785KB) (
510
)
Related Articles

Metrics
To quantitatively evaluate the partial similarity models of water flooding, a new numerical approach of sensitivity analysis is proposed for the sensitivity of the relaxed dimensionless parameter. The sensitivity factor quantifying the dominance degree of the relaxed dimensionless parameter is defined. By solving the dimensionless governing equations including all dimensionless parameters, the sensitivity factor of each relaxed dimensionless parameter is calculated for each partial similarity model, thus the dominance degree of the relaxed one is quantitatively determined. Based on the sensitivity analysis, the influence coefficient of the partial similarity model is defined as a criterion to evaluate each partial similarity model. The partial similarity model with the smallest influence coefficient can be singled out. Results show that the precision of the partial similarity model is not only determined by the number of dimensionless parameters but also by the relative relaxation quantity.
Education Study
Method Technique of Geometric Stability Framed Constitute Analysis in Plane system
2009, 31(2): 8081. DOI:
10.6052/100008792008046
Asbtract
(
1174
)
PDF
(458KB) (
1118
)
Related Articles

Metrics
Research in Teaching of Finite Element Method for Aerospace Structures
Zhiping Qiu
2009, 31(2): 8788. DOI:
10.6052/100008792008057
Asbtract
(
1226
)
PDF
(881KB) (
809
)
Related Articles

Metrics
The Finite Element Method (FEM) is one of the basic classes for undergraduate teaching in mechanics. For the undergraduate who major is aeronautics or astronautics, especially, the FEM is a necessary tool in scientific research and engineering practice in the future. By analyzing the course’s features, roles, goals and some problems existing in the teaching at present, this article gives some suggestions on teaching reform in course system, course content, teaching methods and assessment methods etc. The purpose is cultivating students’ interest and ability to innovate. All that will make one learn and master the FEM more comprehensively and profoundly.
Application study
SINGLE COMPONENT MULTIPHASE DISPLACEMENT WITH LATTICE BOLTZMANN MODELS
2009, 31(2): 3134. DOI:
10.6052/100008792008071
Asbtract
(
1032
)
PDF
(1515KB) (
640
)
Related Articles

Metrics
By introducing fluidfluid and fluidsolid surfaces interactions, the process of the nonwetting vapor phase displacing completewetting liquid phase in twodimensional porenetworks is simulated based on the ShanChen single component multiphase model of lattice Boltzmann method. The fluid interfaces form naturally and the displacement is of capillary fingering. With the capillary number increasing, the viscous force becomes more and more dominating and the sizes of the pores invaded by vapor decrease, leading to rich behaviors of the displacement. With the imposition of the gravity, the gravity plays a stabilizing role on the vapor invasion front.
PROGRESSIVE FAILURE ANALYSIS AND RESIDUAL LIFE PREDICTION FOR FUEL
2009, 31(2): 4649. DOI:
10.6052/100008792008080
Asbtract
(
1279
)
PDF
(752KB) (
732
)
Related Articles

Metrics
The progressive failure analysis and residual life prediction of composite fuel tank are an important part of safety evaluations of RLV. In this paper, based on classical laminates theory, analytic and token models of composite fuel tank are built. By the finite element software ABAQUS, the progressive failure analysis is carried out and the residual life of a fuel tank is predicted. Compared with literature data, good agreements are obtained, which validates the methods proposed in the paper.
STUDY ON THE ACOUSTIC EMISSION MODEL OF WOOD DAMAGE
2009, 31(2): 7477. DOI:
10.6052/100008792008187
Asbtract
(
1178
)
PDF
(698KB) (
616
)
Related Articles

Metrics
There is a quantitative relationship between damage and acoustic emission in wood. Based on damage theory and the acoustic emission signal in wood with defects and cracks in different damage phases, this paper establishes wood mechanics models of damage evolution under alternating load and static load, as two kinds of common situations. Analytical results agree with lumber's actual situation. With special characteristics of the acoustic emission, wood mechanics model of damage evolution with is established, which can be used to forecast the damage in advance, and it is shown that inhomogeneity is one of the main causes of damage.
THE ANALYSIS AND APPLICATION OF DOUBLE LAYER CONTACT FINITE ELEMENT ABOUT ROD AND TUBING STRING IN WELL BORE
Yue Qianbei
2009, 31(2): 3539. DOI:
10.6052/100008792008276
Asbtract
(
1499
)
PDF
(833KB) (
720
)
Related Articles

Metrics
Constructing the double layer multidirectional contact gap element to describe the random contact problem about slim tubing string with inside and outside string, combining with dimensional beam element and adopting variable and equivalent stiffness to solve equations, the contact condition, the contact position, the size of friction and the generalized inner force, stress and deformation in arbitrary well depth of the rod and tubing string were obtained. The arithmetic example about three wells demonstrated that the corrigendum of hang weight in well head was low by 10 percent. Therefor, it supplied reliable computational methods and theoretical references for designing and failure analysis of the rod and tubing string.
Education Study
A new method of solving problems of elasticity with the help of calculator
2009, 31(2): 8486. DOI:
10.6052/100008792008286
Asbtract
(
1564
)
PDF
(428KB) (
822
)
Related Articles

Metrics
A direct method of using polynomial terms as stress function and combining with Matlab program design is introduced for solving problems of elasticity. First the present method has very strong rule for choice stress function, on the other hand, it simplifies the process of determining unknown coefficients. The method improves disadvantages of traditional inverse method or semiinverse method that is necessary that choice stress function through repeated tasting and modifies for obtaining satisfactory results. Meanwhile we denote that some problems doesn't possess polynomial solution. The present approach is successful conjunction example of between modern computer technology and traditional elasticity analytical method. It pump new activity into elasticity analytical method.
Application study
NUMERICAL ANALYSIS FOR TYMPANOSTOMY TUBE IN HUMAN EAR
Li Sheng
2009, 31(2): 6064. DOI:
10.6052/100008792008293
Asbtract
(
1244
)
PDF
(924KB) (
645
)
Related Articles

Metrics
Tympanostomy tube is an effective treatment for secretory otitis media. There have been very few analyses of the biomechanical behavior of the ventilation tube. In this paper, a threedimensional finite element model of the human ear is established, including the external ear canal, tympanic membrane, tympanostomy tube, ossicular bones, middle ear suspensory ligaments/ muscles, and inner ear fluid, which can describe the complicated structures and boundary conditions. The finite element model is used to analyze the displacement change of tympanic membrane and stapes footplate. At the same time, it is found that the presence of tympanostomy tube significantly affects the displacement vibration of the tube. The effect of tympanostomy tube on sound transmission is explained based on numerical method. The results may be useful to the therapy of secretory otitis media and the design of ventilation tube.
Education Study
A NEW MECHANICAL EXPERIMENTMEASUREMENT OF STRESSES IN HOMOGENEOUS CURVED BEAMS AND COMPOSITE CURVED BEAMS
2009, 31(2): 8991. DOI:
10.6052/100008792008295
Asbtract
(
1360
)
PDF
(677KB) (
807
)
Related Articles

Metrics
A new experiment equipment of measuring stress for homogeneous curved beams and composite curved beams is developed. This achievement of scientific research will be applied to educational experiment. Problems in engineering structures are introduced in the new experiment. Hence, it provides with an opportunity for students to improve their practical ability. The differences of curved beams, composite curved beams and straight beams can be found in the experiment. The present equipment can be used to measure the normal and shear stresses in simply supported curved beam made of steel and composite curved beam of steel and copper with trapezoid cross sections. The concentrated force is applied at the arch top of the curved beams. Good agreement between the experiment measurements and theoretical solutions is found.
Application study
NUMERICAL STUDY ON THE MININGINDUCED WATER OUTBURST IN DEEP TUNNEL WITH FAULTS
2009, 31(2): 6973. DOI:
10.6052/100008792008466
Asbtract
(
1148
)
PDF
(1844KB) (
629
)
Related Articles

Metrics
For mininginduced water outburst in deep tunnel of Hongtoushan Copper Mine, a hydraulic model for rock mass in Copper mine is proposed, based on the hydrogeological conditions in Hongtoushan Copper Mine. The Coupling System of Flow {\&} Solid in Rock Failure Process Analysis is applied to simulate and study the whole process of the initiation of fractures, extension and formation of water inrush pathway. With the analysis of damage distribution, stress and seepage field evolution, the process of the evolution from surrounding rock to inrush pathway is clearly revealed, and the water rush pathways are determined. The work can provide a scientific guide for the support and watertight design of tunnel.
Review
SIMULATION AND DESIGN OF MICROELECTRONIC PACKAGING
2009, 31(2): 110. DOI:
10.6052/100008792008575
Asbtract
(
1630
)
PDF
(4991KB) (
801
)
Related Articles

Metrics
In recent years, the product of semiconductor related technologies tend toward to the direction of high density, high performance, multiphysics and miniaturization characteristics. Furthermore, high reliability, low fabrication cost and timetomarket features are the key elements making microelectronic devices to meet the worldwide highly competitive competition. Facing the aforementioned severe challenges, a new design methodology based on the computer simulation technology should be developed to adapt to the new era of ever so various fabrication processes, system integration and next generation electronic packaging devices. Miniaturization induced technology barriers such as process/material uncertainty, structural complexity, high fabrication cost and long development cycles, etc. make conventional design procedure (experiment based design technology, e.g., tryanderror method) inapplicable. Therefore, nowadays, simulation based designonsimulation design concept has been widely adopted as the mainstream technology by worldwide semiconductor related companies and institutions.
Education Study
Discussion of Serval Issues for Pure Beam Deflection Curve by Metheds of Graph Multiplication and Double Integral
2009, 31(2): 8283. DOI:
10.6052/10000879lxysj2007030
Asbtract
(
1378
)
Related Articles

Metrics
The accuracy key to the deflection curve of a uniform section straight beam subjected to the moment is a circle,however,the answers are both parabolas by metheds of graph multiplication and double integral .The reasons are analysed,and the error is given with a parabola replacing a circle.
A Discussion on One Section of Simplified Textbook of Elasticity
2009, 31(2): 9293. DOI:
10.6052/10000879lxysj2007447
Asbtract
(
1149
)
Related Articles

Metrics
The analysis of section relative displacement in antisymmetric statically indeterminate frame without external restrctions
2009, 31(2): 7879. DOI:
10.6052/10000879lxysj2007531
Asbtract
(
1035
)
Related Articles

Metrics
On the basis of the principle of virtual work, the building of unitload state, when solving section relative displacement in antisymmetric statically indeterminate frame without external restrctions, is analyzed principally. The essential of the unitload method can be understood well by students from the analysis of this paper.
Method Technique of Geometric Stability Framed Constitute Analysis in Plane system
2009, 31(2): 8081. DOI:
10.6052/10000879lxysj2008046
Asbtract
(
1028
)
Related Articles

Metrics
Research in Teaching of Finite Element Method for Aerospace Structures
Qiu Zhiping & strXing & Xiaojun Wang Qi Wuchao
2009, 31(2): 8788. DOI:
10.6052/10000879lxysj2008057
Asbtract
(
1098
)
Related Articles

Metrics
The Finite Element Method (FEM) is one of the basic classes for undergraduate teaching in mechanics. For the undergraduate who major is aeronautics or astronautics, especially, the FEM is a necessary tool in scientific research and engineering practice in the future. By analyzing the course’s features, roles, goals and some problems existing in the teaching at present, this article gives some suggestions on teaching reform in course system, course content, teaching methods and assessment methods etc. The purpose is cultivating students’ interest and ability to innovate. All that will make one learn and master the FEM more comprehensively and profoundly.
A new method of solving problems of elasticity with the help of calculator
YuChuan JIANG
2009, 31(2): 8486. DOI:
10.6052/10000879lxysj2008286
Asbtract
(
1487
)
Related Articles

Metrics
A direct method of using polynomial terms as stress function and combining with Matlab program design is introduced for solving problems of elasticity. First the present method has very strong rule for choice stress function, on the other hand, it simplifies the process of determining unknown coefficients. The method improves disadvantages of traditional inverse method or semiinverse method that is necessary that choice stress function through repeated tasting and modifies for obtaining satisfactory results. Meanwhile we denote that some problems doesn't possess polynomial solution. The present approach is successful conjunction example of between modern computer technology and traditional elasticity analytical method. It pump new activity into elasticity analytical method.
A NEW MECHANICAL EXPERIMENTMEASUREMENT OF STRESSES IN HOMOGENEOUS CURVED BEAMS AND COMPOSITE CURVED BEAMS
Yu Aimin
2009, 31(2): 8991. DOI:
10.6052/10000879lxysj2008295
Asbtract
(
1311
)
Related Articles

Metrics
A new experiment equipment of measuring stress for homogeneous curved beams and composite curved beams is developed. This achievement of scientific research will be applied to educational experiment. Problems in engineering structures are introduced in the new experiment. Hence, it provides with an opportunity for students to improve their practical ability. The differences of curved beams, composite curved beams and straight beams can be found in the experiment. The present equipment can be used to measure the normal and shear stresses in simply supported curved beam made of steel and composite curved beam of steel and copper with trapezoid cross sections. The concentrated force is applied at the arch top of the curved beams. Good agreement between the experiment measurements and theoretical solutions is found.
Application study
Simulated numerically of influence of the inner structure of ultrasonic nozzles on the characteristics of the Air Miller
2009, 31(2): 1721. DOI:
10.6052/10000879lxxb2007623
Asbtract
(
1097
)
Related Articles

Metrics
The paper optimizes the structure and parameters of nozzle at jet mill device with software and theories of engineering thermodynamics examining the performance of the designed nozzle by simulating its flow fields with liquid simulated software as well as discussing the effection of passage shape and diffuse angle on supersonic nozzle. The optimized nozzle was then designed to be one with opening pressure of 3.5MPa and opening diameter of 6mm after comparing different simulations. When changing between 8°and 12°, the diffuse angle poses little effect on the performance of the designed supersonic nozzle. And when it is of curve shape, the passage shape betters the performance of the supersonic nozzle.
MIXED MODE DYNAMIC STRESS INTENSITY FACTORS OF CRACKED STRAIGHT THROUGH FLATTENED BRAZILIAN DISC SPECIMENS
2009, 31(2): 4045. DOI:
10.6052/10000879lxysj2007382
Asbtract
(
1544
)
Related Articles

Metrics
In order to establish a standard for the test of mixed mode dynamic fracture of rock with the cracked straight through flattened Brazilian disc (CSTFBD) specimen, we use finite element method first to check the related results in literature on the cracked straight through Brazilian disc specimen (CSTBD). The III mixed mode dynamic stress intensity factors (SIFs) of the two kinds of discs with different dimensionless crack lengths (i.e. the half length of the crack normalized by the radius of the specimen) are obtained to show that the differences of the dynamic SIF's time history between these two kinds of specimens are within 10{\%}, and the numerical method used in this paper is valid. Then for CSTFBD specimens, the III mixed ratio, the angle of crack initiation, and the loading angle for pure mode II fracture test are obtained. The results are useful for mixed mode dynamic fracture test of CSTFBD, including specimens preparation, the location and directional alignment of the strain gages, as well as the estimation for the crack initiation time and the crack initiation direction.
INFLUENCE OF THE VOID DISTRIBUTION ON MACRORESPONSES OF FUNCTIONALLY GRADED PLATES
2009, 31(2): 5559. DOI:
10.6052/10000879lxysj2007503
Asbtract
(
1190
)
Related Articles

Metrics
Complex microstructures of functionally graded materials and their geometry make related strucutres more complex than plates, cylindrical shells and spherical shells. Therefore, the analytic solution of functionally graded structure is difficult to obtain, and the approximate solution and other calculation methods are used frequently. A new microelement method for the analysis of functionally graded structures is suggested to establish a quantitative relation between the macrocharacteristics and microstructures of functionally graded materials, and different combinations of materials for different macrocharacteristics can be found. By this microelement method, the influence of voids on the macroresponses can be analyzed. The threedimensional distributions of mechanical quantities of the functionally graded plates with different distributions, forms and positions of the voids are given, a transscale analysis between microconstitution and macroresponse of the functionally graded materials and structures can be carried out.
A NEW THEORETICAL MODEL FOR ARMORPIERCING MECHANICS
LiPeng WU
2009, 31(2): 2226. DOI:
10.6052/10000879lxysj2007511
Asbtract
(
1291
)
Related Articles

Metrics
Penetration mechanics is important both as a science and in practice of military engineering. For a quasisteady penetration of long rod projectile into semiinfinite thick target, a simplified model is developed, where the bullet incorporated mushroom head consists of unbroken zone, crush zone and hole dilating zone, and the target consists of hole dilating zone, crush zone and unbroken zone, with the strain rate effect being considered. A set of ODE is obtained through conservation laws of every part. Through theoretical analysis and calculation, the influences of the crush strain rate, crash strength of the projectile and the strain rate effect of the crash strength of the target on penetration depth are analyzed. The excellent agreement of the calculation results and the experiment shows the effectiveness of the simplified model.
WIND LOADS ON MULTI NATURAL DRAFT COOLING TOWERS IN A POWER PLANT
Yinan Li
2009, 31(2): 6568. DOI:
10.6052/10000879lxysj2008018
Asbtract
(
1223
)
Related Articles

Metrics
Natural draft cooling tower is a highrise thin shell structure. The displacement in the top of the cooling tower can be tens of centimeters under wind loads, several times of the wall thickness. Cooling tower is very sensitive to wind loads, especially in multitowers conditions, where the wind velocity, wind pressure distribution and airflow among towers are quite complex. On the basis of the experiment results on irregular multitowers, this paper put forward some proposals about determining wind loads of natural draft cooling tower in multi towers conditions.
ESTIMATING THRESHOLDS OF DAMAGES BASED ON NATURAL FREQUENCY METHOD
2009, 31(2): 5054. DOI:
10.6052/10000879lxysj2008023
Asbtract
(
1208
)
Related Articles

Metrics
The damage thresholds obtained by natural frequency method can be used as a criterion to justify the usefulness of practical engineering structure. The natural frequency method consists of analyzing the influential factors of the damage, and a cantilever beam model is taken as an example. Both numerical and theoretical results indicate that, if the frequency measurement error is known, this method can be used to estimate the thresholds, during the early period of damage. The thresholds obtained by this method agree with the numerical results very well.
DESIGN OF PARTIAL SIMILARITY MODELS AND THEIR EVALUATION METHOD IN WATER FLOODING PHYSICAL SIMULATION
Yuhu Bai
2009, 31(2): 2730. DOI:
10.6052/10000879lxysj2008034
Asbtract
(
1112
)
Related Articles

Metrics
To quantitatively evaluate the partial similarity models of water flooding, a new numerical approach of sensitivity analysis is proposed for the sensitivity of the relaxed dimensionless parameter. The sensitivity factor quantifying the dominance degree of the relaxed dimensionless parameter is defined. By solving the dimensionless governing equations including all dimensionless parameters, the sensitivity factor of each relaxed dimensionless parameter is calculated for each partial similarity model, thus the dominance degree of the relaxed one is quantitatively determined. Based on the sensitivity analysis, the influence coefficient of the partial similarity model is defined as a criterion to evaluate each partial similarity model. The partial similarity model with the smallest influence coefficient can be singled out. Results show that the precision of the partial similarity model is not only determined by the number of dimensionless parameters but also by the relative relaxation quantity.
SINGLE COMPONENT MULTIPHASE DISPLACEMENT WITH LATTICE BOLTZMANN MODELS
2009, 31(2): 3134. DOI:
10.6052/10000879lxysj2008071
Asbtract
(
978
)
Related Articles

Metrics
By introducing fluidfluid and fluidsolid surfaces interactions, the process of the nonwetting vapor phase displacing completewetting liquid phase in twodimensional porenetworks is simulated based on the ShanChen single component multiphase model of lattice Boltzmann method. The fluid interfaces form naturally and the displacement is of capillary fingering. With the capillary number increasing, the viscous force becomes more and more dominating and the sizes of the pores invaded by vapor decrease, leading to rich behaviors of the displacement. With the imposition of the gravity, the gravity plays a stabilizing role on the vapor invasion front.
PROGRESSIVE FAILURE ANALYSIS AND RESIDUAL LIFE PREDICTION FOR FUEL
Wang Zhengqing
2009, 31(2): 4649. DOI:
10.6052/10000879lxysj2008080
Asbtract
(
1224
)
Related Articles

Metrics
The progressive failure analysis and residual life prediction of composite fuel tank are an important part of safety evaluations of RLV. In this paper, based on classical laminates theory, analytic and token models of composite fuel tank are built. By the finite element software ABAQUS, the progressive failure analysis is carried out and the residual life of a fuel tank is predicted. Compared with literature data, good agreements are obtained, which validates the methods proposed in the paper.
STUDY ON THE ACOUSTIC EMISSION MODEL OF WOOD DAMAGE
2009, 31(2): 7477. DOI:
10.6052/10000879lxysj2008187
Asbtract
(
1106
)
Related Articles

Metrics
There is a quantitative relationship between damage and acoustic emission in wood. Based on damage theory and the acoustic emission signal in wood with defects and cracks in different damage phases, this paper establishes wood mechanics models of damage evolution under alternating load and static load, as two kinds of common situations. Analytical results agree with lumber's actual situation. With special characteristics of the acoustic emission, wood mechanics model of damage evolution with is established, which can be used to forecast the damage in advance, and it is shown that inhomogeneity is one of the main causes of damage.
THE ANALYSIS AND APPLICATION OF DOUBLE LAYER CONTACT FINITE ELEMENT ABOUT ROD AND TUBING STRING IN WELL BORE
Qianbei Yue
2009, 31(2): 3539. DOI:
10.6052/10000879lxysj2008276
Asbtract
(
1473
)
Related Articles

Metrics
Constructing the double layer multidirectional contact gap element to describe the random contact problem about slim tubing string with inside and outside string, combining with dimensional beam element and adopting variable and equivalent stiffness to solve equations, the contact condition, the contact position, the size of friction and the generalized inner force, stress and deformation in arbitrary well depth of the rod and tubing string were obtained. The arithmetic example about three wells demonstrated that the corrigendum of hang weight in well head was low by 10 percent. Therefor, it supplied reliable computational methods and theoretical references for designing and failure analysis of the rod and tubing string.
NUMERICAL ANALYSIS FOR TYMPANOSTOMY TUBE IN HUMAN EAR
Sheng Li Yingxi Liu Sun Xiuzhen
2009, 31(2): 6064. DOI:
10.6052/10000879lxysj2008293
Asbtract
(
1177
)
Related Articles

Metrics
Tympanostomy tube is an effective treatment for secretory otitis media. There have been very few analyses of the biomechanical behavior of the ventilation tube. In this paper, a threedimensional finite element model of the human ear is established, including the external ear canal, tympanic membrane, tympanostomy tube, ossicular bones, middle ear suspensory ligaments/ muscles, and inner ear fluid, which can describe the complicated structures and boundary conditions. The finite element model is used to analyze the displacement change of tympanic membrane and stapes footplate. At the same time, it is found that the presence of tympanostomy tube significantly affects the displacement vibration of the tube. The effect of tympanostomy tube on sound transmission is explained based on numerical method. The results may be useful to the therapy of secretory otitis media and the design of ventilation tube.
NUMERICAL STUDY ON THE MININGINDUCED WATER OUTBURST IN DEEP TUNNEL WITH FAULTS
2009, 31(2): 6973. DOI:
10.6052/10000879lxysj2008466
Asbtract
(
1128
)
Related Articles

Metrics
For mininginduced water outburst in deep tunnel of Hongtoushan Copper Mine, a hydraulic model for rock mass in Copper mine is proposed, based on the hydrogeological conditions in Hongtoushan Copper Mine. The Coupling System of Flow {\&} Solid in Rock Failure Process Analysis is applied to simulate and study the whole process of the initiation of fractures, extension and formation of water inrush pathway. With the analysis of damage distribution, stress and seepage field evolution, the process of the evolution from surrounding rock to inrush pathway is clearly revealed, and the water rush pathways are determined. The work can provide a scientific guide for the support and watertight design of tunnel.
Review
ADVANCES IN HYPERVELOCITY IMPACT DYNAMICS AND SPACECRAFT PROTECTION RESEARCH
LI Yiyong
2009, 31(2): 1116. DOI:
10.6052/10000879lxysj2008017
Asbtract
(
1238
)
Related Articles

Metrics
Hypervelocity impact dynamics and spacecraft protection as an important part of hypervelocity impact technology, is reviewed in this paper. Its research background is outlined. Its research progress covers the following five aspects: making hole in the thick board, penetration in the critical thick board, forming debris cloud from the thin board, experimental simulation technique and numerical simulation technique. The damage effect of hypervelocity impact spacecraft is analyzed. The spacecraft protection requirements are given, and the project design and performance of the spacecraft protection structure are discussed.
SIMULATION AND DESIGN OF MICROELECTRONIC PACKAGING
2009, 31(2): 110. DOI:
10.6052/10000879lxysj2008575
Asbtract
(
1496
)
Related Articles

Metrics
In recent years, the product of semiconductor related technologies tend toward to the direction of high density, high performance, multiphysics and miniaturization characteristics. Furthermore, high reliability, low fabrication cost and timetomarket features are the key elements making microelectronic devices to meet the worldwide highly competitive competition. Facing the aforementioned severe challenges, a new design methodology based on the computer simulation technology should be developed to adapt to the new era of ever so various fabrication processes, system integration and next generation electronic packaging devices. Miniaturization induced technology barriers such as process/material uncertainty, structural complexity, high fabrication cost and long development cycles, etc. make conventional design procedure (experiment based design technology, e.g., tryanderror method) inapplicable. Therefore, nowadays, simulation based designonsimulation design concept has been widely adopted as the mainstream technology by worldwide semiconductor related companies and institutions.