Due to fluid excitation and the vibration of connected equipment, industrial pipelines are prone long-term medium-high frequency small amplitude vibration. Magnetorheological (MR) dampers with a multi-stage squeeze plate structure were proposed solve problem in pipeline. The dynamic characteristics pipeline analyzed determine installation position MR dampers. mechanical properties squeeze-mode tested, hyperbolic tangent model damper was established. control built for simulation analysis. In...

Abstract Commercial vehicles are usually equipped with suspension seats to improve ride comfort. As a semi-active intelligent device, magnetorheological damper can effectively seat comfort when applied suspension. Firstly, novel built-in valve (MRVD) based on the squeeze mode of fluid (MRF) is designed, which integrates (MRV) into piston. This structure adopts bidirectional controllable flow channel, double coil, and chamber. Secondly, mathematical model MRVD derived Bingham plastic MRF....

Piperazine pyrophosphate (PAPP) was mixed in polyamide 6 (PA6) to investigate its flame retardant properties. The PAPP characterised by Fourier transform infrared (FT-IR), elemental analysis, proton nuclear magnetic resonance (1H-NMR) spectroscopy and thermogravimetric analysis (TGA). TGA results of indicated it had a high P element content good thermal stability. retardancy PA6/PAPP also TGA, limiting oxygen index (LOI), UL-94 vertical test microscale combustion calorimetry (MCC). showed...

Abstract Due to the high frequency hardening effect in applications of satellite and precision vibration isolation, it is an urgent need analyze improve magnetorheological (MR) performance MR damper under small-stroke medium-high excitations. In this paper, a compact with pressure controlled mechanism proposed, analyzed tested. Considering inertial, pre-compression compressibility fluid, dynamic physic model established output characteristics pre-compressions And then, critical between...

This paper presents a positioning error model and control compensation scheme for six-degree-of-freedom (6-DOF) micro-positioner based on compliant mechanism piezoelectric actuators (PZT). The is established by means of the kinematic complete differential coefficient theory, which includes relationships between three typical errors (hysteresis, machining measuring errors) total error. quantitative analysis demonstrated through several experimental studies. Afterwards, an inverse Presiach...

Abstract Semi-active seat suspension with a magnetorheological (MR) damper has been popular study issue in recent years. Since the response time delay of MR can reduce control effect and even make vibration more severe, there is an urgent need to compensate for delay. In this paper, gray prediction introduced into commercial vehicle suspension. A skyhook controller designed This proposed does not rely heavily on parameter optimization requires fewer state variables than other typical...

The piezoelectric-actuated flexure-based compliant platform is commonly adopted in many fields of micro and nanotechnology. In this paper, bond graph modeling, kinematic dynamic characteristics a micro-/nano system are investigated. During the model piezoelectric actuator (PZT) derived by considering both electrical domain mechanical domain. Considering compliances flexure hinges elastic linkages, as well input ends, for bridge-type displacement amplification mechanism established combining...

Magnetorheological (MR) grease has advantages of the anti-settlement behavior and excellent sealing property compared with conventional MR materials. However, rheological behaviors effect shear yield stress are too small to limit further applications grease. This paper proposes a composite lithium-based boric acid-hydroxyl stearic acid improve behaviors. Eight different samples ratios mass between lithium stearate borate prepared by saponification method. The tested discussed qualitative...

Under small amplitude and medium-high frequency excitations, mechanical properties of squeeze mode magnetorheological (MR) damper change obviously which are different from general properties. Performance will be attenuated seriously is known as the high hardening effect. In this paper, performance a novel MR with pre-compression mechanism under such excitations has been analyzed qualitatively quantitatively. A proposed to improve performance. Then, considering viscoelasticity, inertial...

Abstract Vibration isolation performance of seat suspension plays a critical role in protection drive’s physical health as the last barrier. In this paper, integrated magnetorheological (MR) dynamic tuned mass damper (TMD) is firstly designed and utilized into suspension. A semi-active co-control algorithm with MR TMD designed, analyzed validated by comparative experiments. The models two devices have been tested fitted. Comparing simulation experimental results under various excitations...

Abstract As a novel material, magnetorheological fluid porous fabric composite (MRF-PF) has not been further analyzed and modeled. In this paper, mechanical properties of MRF-PF are quantitatively qualitatively with constitute model. Considering the wall slip, viscoelasticity internal network MRF-PF, model is derived firstly which can describe performance precisely. According to experimental results, different from conventional MRF. Shear stress τ decreases first, then increases slowly at...

Abstract Both system dynamics simulation and numerical analysis have been conducted to study the effect of different automotive starting modes on clutch thermo-mechanical coupling characteristics. Based six-degree-of-freedom dynamic model driveline, responses were obtained under four that are determined by changes pressure between friction plate plate. According results responses, transient thermal pair performed using finite element method assuming car is driving congested roads. The show...

The piezo-actuated micro-/nanopositioning stages are often used in the current precision engineering applications, and coupling deformation under gravity of stage is critical to error analysis. Considering torsional bending flexure hinges, error’s analytical model positioning along Z-axis derived by using virtual work principle elastic beam theory. performance proposed theoretical analyzed verified comparison between two common materials, quantities piezoelectric actuators also with impact...

In this paper, magnetorheological (MR) porous fabric composites were prepared by using non-woven fabrics pretreated with lithium stearate. Due to the structure of and good stability stearate, mechanical properties sedimentation composite have been improved. The viscosity, shear stress dynamic viscoelasticity different samples analyzed rheological tests. results indicate that containing stearate are improved compared MRF (magnetorheological fluid) sample, its under non-working conditions is...