Advanced Materials Research Vol. 681

Abstract: The indoor road simulation test system test cycle is short, good reproducibility of the test results, confidentiality, etc., more and more attention in the vehicle industry. Analyzed by electro-hydraulic servo system of road simulation servo amplifier, electro-hydraulic servo valve, hydraulic cylinder and countertops and displacement transducer, The mathematical model of the system is established. The fuzzy model that comply with control law is designed. By unit step response simulation experiments, it is to be verified that the fuzzy control electro-hydraulic servo road simulation system is able to work better. It is a new attempt in roads simulation control strategy.

Abstract: To set up the virtual prototype of a gear train system in the dynamic analysis software ADAMS, the torsional vibration model of a gear pair was transformed into an equivalent transmission model in which a multi-body model was established in ADAMS and its meshing force solution model was established in Simulink. The time-varying mesh stiffness, gear clearance, meshing errors and other non-linear factors can be included in the gear meshing feedback model, more importantly, the influence of gear speed fluctuation on the time-varying mesh stiffness was taken into consideration. The simulation results contrastively prove the feasibility of co-simulation for obtaining the dynamic characteristics of gear meshing process.

Abstract: Considering the flexibility performance of lightweight slender axle in Delta parallel mechanisms, the effects of the elastic deformation on the kinematic accuracy of the mechanism are calculated based on the virtual prototype technology. Firstly, the 3D model of the mechanism is built via ADAMS software. Secondly, the geometric model of the driving rod is imported into ANSYS software to get meshed and generate the modal neutral files. Then, getting back to ADAMS, the original rigid component is replaced with the flexible body which constraint and driving is added to lately. At last, the rigid-flexibility hybrid model of the mechanism is built. Each frequency and vibration mode of the flexible body is calculated, using the simulation capabilities of the software. Furthermore, changes in motion accuracy of the mechanism under the effect of the force-elastic coupling are analyzed comparatively.

Abstract: The working mode of constant-pressure radial piston pump includes the mode of constant flow and constant pressure. The dynamic model of stator vibration was established and the analysis was made on the stator vibrating velocity in time domain to the two modes. Measurement mechanism was designed to test the vibration of stator of JB32H-type radial piston pump. It is concluded from the analysis and test results that the velocity of stator vibrates periodically on the two modes. The maximum amplitude on the mode of constant pressure is smaller than the one on the mode of constant flow. The conclusions are helpful to the noise control of piston pump.

Abstract: According to Japan Railway seismic design code, truss finite element model is established considering the pile components and foundation nonlinear finite element model in this paper, an analysis on the ultimate horizontal bearing capacity of bridge pile foundation of passenger dedicated line is made and the results of m-method calculation are compared. The analysis results show that: when horizontal force at the top of pier is larger, with the pile side soil horizontal and vertical force continuously into the plastic, the calculation results differ greatly with two seismic specification; the pier top level force-displacement skeleton curve considered pile-soil interaction is available in trilinear description, the analysis results can provide a theoretical basis for the seismic analysis of the pile foundation under rare earthquake.

Abstract: The effect of torsional pre-strain on 35CrMo tensile property is study in this paper. A series of 35CrMo tensile test under different torsional deformation, 0°、45°、135°、225°、405° and 585°,are finished. The tensile stress-torsional deformation curve and tensile stress uncertainty evaluation are finished after analyze, according to the Kolmogorov and Grubbs criterion, of test results is done. It is found that tensile stress increases while the torsional deformation is not bigger than 405°, the tensile stress decreases obviously when torsional deformation becomes 585°. Uncertainty evaluation is helpful to understanding and recognition the influences on metal material mechanics property test.

Abstract: The sensibility analysis of the factors to crack growth life has been done. The results show that the input parameters have the following precedence ordering: fatigue crack growth threshold, fracture spectrum, initial crack, fracture toughness, the sensibility values are 11.25, 8.5417, 0.8333, 0.1125, respectively. The model parameters have the following precedence ordering: n, p, C, q. the sensibility values are 6.0417, -3.9583, 1.25, 0.1812, respectively. The reliability analysis was conducted by Monte-Carlo method, the results show that the crack growth life accord with lognormal distribution. The lives with different reliability were obtained. The reliability analysis results of the crack growth life has provided the data for a hybrid approach based on a mixture of the traditional safe-life and damage tolerance techniques which were used as an optimal strategy for ensuring the helicopter structural integrity.

Abstract: In our study, a new kind of material was prepared by melt blending with PVC as the matrix and carbon black (CB) as the filler. With the amount of CB increasing, the notched impact strength of composite increased greatly, however the tensile strength declined. When the amount of CB was 30%, the notched impact strength of composite was 9.66 KJ/m2, the tensile strength dropped from 48.3MPa to 33.2MPa. The distribution of CB in the PVC matrix is relatively uniform and no large agglomeration in the PVC matrix.

Abstract: In our study, a new kind of foam composite was prepared by melt blending with PVC as the matrix and carbon black (CB) as the filler, the standard-spline was made in the dumbbell system prototype. Tensile strength and elongation at break were measured at 25°C。When the CB was added greater than 2.0%, with the increase of CB added, the determination of sample mechanical index began to decline, when the CB content was greater than 9%, tensile strength and elongation at break of the composites remained basically unchanged.

Abstract: This paper reviews the characteristics of smart materials, such as Piezoelectrics (PZT), shape memory alloys (SMA) and mganetostrictive materials (Terfenol-D). Since the properties of these smart materials vary greatly in terms of free strain and actuation stress, there is a need to identify the optimum smart materials for a particular application. From the review and comparison of different types of pumps (based on PZT, SMA and Terfenol-D), we recognize that these pumps have their unique advantages in specific application fields.