The linear parameter varying (LPV) system model of the lateral-directional dynamics for large envelope flight of modular aircraft including various configurations was built. The validity of the aircraft LPV model was verified by the comparison of dynamic simulation between the LPV model and the nonlinear...

Many cases show that multiple injections fracturing serves as an effective method to increase the probability of creating complex fracture network for shale gas reservoirs. However, its mechanism is unclear. This paper, therefore, intends to use numerical simulation and theoretical models to explore...

Core flood experiment is commonly used to study the fluid seepage law in porous media for enhanced oil recovery, but the characteristics of fluid flow are hard to be visually described. In this paper, an advanced visual displacement system was developed and optimized to observe the shapes of flow front...

The continuous wave pulse generator with rotary valve is an advanced and key equipment in high-rate measurement while drilling (MWD) and logging while drilling (LWD) telemetry systems. It generates an encoded mud pressure wave signal to transmit real-time information from down-hole to surface. For the...

In order to solve the problems of the classical system reliability assessment method in dealing with complex system with small samples, such as multilevel approximation, insufficiency and singleness of information, take the success or failure products as an example, the theory of multi-source reliability...

In this study, the aerodynamic characteristics of dragonfly wing corrugation in hovering flight are investigated using the computational fluid dynamics (CFD) methods. Three corrugated cross sections of the right forewing of a dragonfly (Aeshna cyanea) are considered. The effects of wing corrugation are...

In many occasions of the practical engineering, the equipment of reciprocating rectilinear movement at high frequency is used commonly, which usually is completed by the slider-crank mechanism. But there is big friction force between the guide rail and the block in this mechanism, thus the big friction...

A numerical simulation method for the flight dynamic response of the elastic aircraft flying through the wind field over complex terrain is developed in this paper. The complex terrain model is established by the spline method based on the contour line of the map. The wind field is then simulated by...

This paper aims to simulate two stretching methods adopted in plantar fasciitis treatment in MSC.ADAMS, Achilles tendon stretch and plantar fascia stretch. Clinical evidence has been accumulated that stretching is effective in relieving heel pain caused by plantar fasciitis. While plantar fascia stretching...

Strain localization in sand is modelled as the event of two-phase coexistence. Shear bands pertain to the high-strain phase of materials. And other regions outside bands pertain to the low-strain phase. Inside each phase the equilibrium equations must be satisfied. Across interfaces between the two phases,...

The wedge-raceway contact mechanical model, considering centrifugal force of wedge and the eccentricity of the inner ring and the outer ring of the one-way clutch, is established based on Hertz contact theory. The normal contact stiffness of the sprag one-way clutch is calculated by Newton iterative...

Numerical simulation was applied to study the effects of changing geometric parameters, which were slot height G and axial length of outer collar L, on jet attachment of counter-flow thrust vectoring nozzle in zero attack angle and subsonic conditions. Combined internal flow characteristics of different...

In this paper, the torsional vibration suppression is investigated for a gear system installed with a damping ring. The dynamic model of the gear-damping ring system is established, where the friction between the gear and the ring is described by the Stribeck model. The harmonic balance method is employed...

When simulating crack propagation process using the finite element method, we need to create singularity grids at the crack tip. And with the increase in crack length, we need a re-division of grids. This makes the calculation very complicated. The extended finite element method (XFEM) is an effective...

Gearbox is a critical component of mechanical equipment. Centralized fault and distributed fault are the two typical faults of gearbox. Both faults have their own features. In order to know them better, the characteristics in the time and frequency domain of the vibration signal were analyzed in detail....

To protect occupant under emergency landing, the seat/restraint system of airplane must be designed to has crash-resistant ability. The dynamic simulation can get the damage and impact response characteristics. The results can be helpful to modify the seat/restraint system and seat dynamic test.

Crankshaft assembly, as one of the most important parts of the engine, always suffers many kinds of cyclic loading during service. Due to the higher requirements for dynamic property of mechanical system, it is necessary to work on multi-body dynamics simulation of crankshaft assembly quick and accurately....

In order to understand the behavior of Jinan Yellow River Bridge more accurately and evaluate the bridge health, we change the sensors of the health monitoring system so that the data collected are more detailed and comprehensive. The monitoring data are analyzed synthetically. And then, based on this,...

During the cruise process of prionace glauca, its pectoral fins play an important role in keeping balance and stability of its body. The research on the fluid-solid coupling of prionace glauca pectoral fins is of important value to optimizing the design of the AUV and other marine engineering equipment....

A mathematical model of adaptive generalized chaotic synchronization(AGCS) was established to investigate the synchronization between a multi-degree freedom non-autonomous(nonlinear vibration) driving system and an autonomous chaotic (Lorenz) response system. Within the heterostructure synchronization...

This paper deals with the reflection and refraction of finite-amplitude acoustic waves obliquely incidents to a plane interface between two lossless fluids. The study is based on the second-order harmonic wave equations in term of displacement potential in Lagrangian coordinate system. Variable parameter...

Identifying non-uniform cracks in plates is a challenging problem worthy of exploration. 2D modal curvature is often utilized to detect damage in plates, but its capability to precisely identify non-uniform cracks has not been resolved well, largely due to two noticeable deficiencies, lack of sensitivity...

Based on the continuous contact force model, the rigid-flexible coupling impact dynamics of a radial rotating flexible beam is investigated. The transversal deformation and nonlinear coupled deformation, which means the longitudinal shortening caused by transversal deformation, is considered. According...

This paper focuses on the free span of submarine pipelines. The vibration differential equation and dynamic characteristic equation of submarine pipelines subjected to axial force and stress analysis were established, and then got the natural frequency. In order to avoid VIV, the vortex shedding frequency...

In this paper, the icing mechanism and force of overhead transmission lines were studied. The inclined parabolic equation of overhead transmission lines was derived and on this basis, calculation methods of sag, long lines and stress had been discussed. The paper got the inclined parabolic form of the...

High thermal stresses developed in coke drums can lead to fatigue crack initiation and subsequently growth until premature drum failure. To predict the fatigue crack initiation lives of coke drums, a cost-efficient method was proposed using Monte Carlo simulation in this paper. Strain data on the critical...

In order to analyze the impact of height adjustment for Vossloh300 fasteners on the rail lateral displacement and the stress of sleeper bumping shoulder, the paper construct the mechanic model and finite element model, the rail lateral displacement and the stress of the sleeper bumping shoulder were...

The flowing bottomhole pressure (FBHP) of gas wells was affected by many factors. Although a lot of research works have been done to predict the FBHP and at least more than ten models were proposed, but no one can effectively provide an accurate results for all ranges of production data and conditions...

Usually a tiltrotator is mounted on the excavator such that the bucket of excavator can not only move in the plane of the excavator attachment, but also deviate from the plane. However, this generated additional bending moment and torque, and what was more, the traditional design method, which is used...

The dynamic response characteristics of the structure are affected by the nonlinear term in the theodolite structure with supporting shaft and bolt fixed connection. The harmonic term caused by nonlinear response has important influence on the measurement accuracy of optical system and the tracking stability...

The distribution characteristics of plume field structure of solid rocket motor could great influence on overall design of rocket, design of launch vehicle, materials selection and so on. Therefore, it is necessary to study structure characteristic of plume field of solid rocket engine. In this paper,...

The human knee cartilage play an important role in the knee joint. Osteoarthritis (OA) are related to knee joint cartilage. So the accurate description of the cartilage constitutive is the most important work for the understanding the cartilage test phenomenon. The role of viscoelasticity of collagen...

In this article a bell mouth junction assembled in front of the test article in practice was simulated by applying ANSYS CFX, the data of relative measurement points was picked up from the simulation result and compared with test data to validate the simulation reliability. Then, aiming to dwindle in...

The friction motion exists generally in the mechanical operation structure. The target of the paper is to predict and optimize the dynamic performance of the mechanical structure via the structure design. The kinetic equation of discrete-node model is established based on the theory of the characteristic...