Resistive network model of the weft-knitted strain sensor with the plating stitch-Part 1: Resistive network model under static relaxation

The resistive network model of the weft-knitted strain sensor with the plating stitch under static relaxation is studied based on the knitted loop structure and circuit principle. The prepared sensors are divided into the sensing area and the non-sensing area. The former consists of the conductive face yarn and the insulated elastic ground yarn, while the latter includes the normal face yarn and the same ground yarn. The loop of conductive face yarn not only produces length-related resistance but also causes the jamming contact resistances along the width and length direction. Besides, the elastic ground yarn has a potential impact on the contact situation of the conductive face yarn at the interlocking point, determining whether the interlocking contact resistance exists. Therefore, two resistive network models have been established accordingly. In addition to the length-related resistance, the first model focused on both the jamming and interlocking contact resistances, while the second one only dealt with the jamming contact resistance. In the case of applying voltage along the two ends of the course, the theoretical calculations of the corresponding network models were performed using a series of equivalent transformations. Finally, the correctness and usability of the two models were verified through experiments and model calculations. It was found that both models can predict that the equivalent resistance increases with the conductive wale number and decreases with the conductive course number. It was implied that the first model’s calculating resistances are closer to the experimental data and lower than those of the second model. The difference in the calculating resistances of the two models would become smaller as the course number increases. Thus, the investigation indicates that the jamming contact resistance has a more considerable influence on the resistive network than the interlocking contact resistance.

Control Characteristics of Haptic Exoskeleton Elbow Module Used in Space Robotised Applications

In this paper the authors present some considerations regarding the necessity and the methods to calibrate an exoskeleton elbow module. Prior researches and studies are indicating that there is a difference between the haptic device force reaction and situation (position and orientation) and similar parameters at the level of the guided or slave robot. The authors are investigating the causes of the pose accuracy and force errors knowing the fact that for some space operations the fidelity of the teleoperation the geometric, kinematic and dynamic parameters are of great importance. The authors propose the measurement of the position accuracy, position repeatability, static relaxation under load, speed and acceleration, force and torque measurement in order to obtain a real correlation between the haptic device and the space robot parameters. Also the authors are considering the investigation of the unwanted vibration and the effect on the teleoperation parameters. Considering the importance of calibration for the improvement of the general accuracy of teleoperation the authors are taking into account the development of several performance indicators as a consequence of the conclusions emerged from the calibration methods study above mentioned. Also they consider very important that the calibration methods must be specific for each application category and therefore moderated performance indicators are envisaged.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Study on Transforming Dynamic Modulus Master Curve into Static Relaxation Modulus Master Curve Basing on the Relaxation Time Spectrum of Asphalt Mixture

In order to transform dynamic complex modulus into static relaxation modulus, an advanced Shear Rheometer is used to get complex modulus master curve of asphalt mixture. Dynamic modulus master curve is transformed into static modulus master curve basing on the relaxation time spectrum. Results show it is feasible that the dynamic modulus master curve can be transformed into relaxation modulus master curve in wide frequency domain basing on the relaxation time spectrum.

Characterization of Shot Peened 2024-T351 Aluminum Alloy

Specimens of 2024-T351 aluminium alloy under different three shot peening intensities were studied. The modifications of the surface layers of the shot peened specimens were investigated through microhardness, surface microstructure and residual stress relaxation after the first and second load cycles under two cyclic loads. No significant changes in microstructure after the three shot peeing intensities were observed with respect to untreated specimens. Rapid residual stress relaxation was observed in specimens after the first cycle. Relaxation of residual stresses occurred within first loading cycles were increased with increasing loading stress amplitude and due to quasi-static relaxation effects.

Viscoelastic Deformation of PC/ABS Alloy

Dynamic Mechanical Analysis (DMA) and static relaxation tests are carried out to study the viscoelastic deformation of PC/ABS alloy with blending ratio of PC to ABS being 50/50. A modified approach is developed to calculate the relaxation modulus of PC/ABS alloy from the DMA experimental results of storage and loss moduli. Comparison of the results obtained from DMA and static relaxation tests is presented and good agreement is found.

A Three-Dimensional Numerical Model for Simulating Deformation and Failure of Blocky Rock Structures

This paper presents a three-dimensional numerical model for simulation of blocky rock structures based on static relaxation approach. The proposed method utilizes static equilibrium equations to calculate the displacements of blocks, compared to Newton’s second law applied by the traditional DEM. In order to obtain displacements simultaneously, the technique of global stiffness matrix is introduced in to form the global equilibrium equations. Because large displacements come from the accumulation of small displacement increments, an iteration procedure is adopted in the calculation. A C++ program is developed based on the proposed algorithm, and an illustrative example is computed for verification.