Applied Mechanics and Materials Vol. 418

Abstract: In this paper, a gripper mechanism with two flexible elements for grasping the objects was investigated. In general, to achieve the good the flexibility and the life strength, the flexible hinges often offer the highest elastic energy store while the lowest stress concentration is also required simultaneously. Therefore, to handle this multi-objective optimization problem, this study used the fuzzy logic based Taguchi method. The two input parameters, namely a vertical force and a horizontal force that primarily influence the displacement and the stress. These were controlled with regard to two-objective functions as the torque of torsional spring and the stress. In addition, formulating two-objective functions was based on the procedure of a pseudo-rigid-body model (PRBM) and the principle of virtual work. The results found that a vertical force of 0.5 lb and a horizontal force of 0.4 lb are favorable parameters for a suggested gripper. Using ANOVA, the results also revealed that a vertical force is the most significant parameter with highest F value of 1.188.

Abstract: This paper presents a method of human detection by Meanshift based on depth map. By analyzing and comprehensively applying segmentation method based on height information to extract moving target and remove the background information from depth map, then find the region of interest (ROIs) with moving target, thus through mean shift method to achieve real-time detection of targets (pedestrian). Depth image has nothing to do with color space and not suffer from the factors such as illumination, shadow effect. In this paper, using the depth image pattern recognition is a good way to overcome the difficulties of visible light image pattern recognition often encountered.

Abstract: The Dow fire and explosion index (F&EI) is universally used in evaluating the hazard category of a process plant, area of exposure, expected losses in case of fire and explosion, etc. In the current procedure, the effects of the safety management measures (SMMs) on the F&EI value are not taken into account. This makes the plant look more hazardous, makes it more spread out, requires more elaborate emergency measures and alarms the public more than is necessary. The objective of this paper is to develop an improved Dows fire explosion index which not only supplemented and detailed the safety compensation coefficient and added the safety management coefficient in the F&EI value. And furthermore, this paper calculates and evaluates quantitatively the fire explosion risk of organic solvent recovery plant in a pharmaceutical factory based on the improved evaluation method. To do this, we have developed the relevant equations and have proved the efficacy of the SMMs by means of an actual case, and the evaluation results are more accurate and scientific.

Abstract: This article presents the application of the non-destructive testing method (so called Bender element test) to measure the shear wave velocity and determine the maximum shear modulus of soft Bangkok clay samples. This research proposes the bender element technique to measure the shear wave velocity by means of piezoelectric ceramic sensors. The details of the bender element test were clearly explained. The laboratory bender element test data of the shear wave velocity were compared with the field test results and show that the field propagating waves pass along layers of higher stiffness while the laboratory test data were performed on small, possible less stiff material. The inversion calculation of the shear wave velocity in the field test is based on a linear elastic isotropic assumption which is not valid for the Bangkok subsoil and might be a second reason for the noticed differences in velocity.

Abstract: This paper purposes a new technique to measure the shear wave velocity by using the piezoelectric film. This piezoelectric film is a very thin, light and high sensitive sensor and is used as a receiving sensor. The details of this new technique and its interpretations on Bangkok clay material are explained. The research found that this new technique is a reasonable technique, giving the shear wave velocity result in good agreement with the shear wave velocity data from the field test.

Abstract: The article deals with dynamic analysis of mechanism HR 3001 used at the lifting and transporting of various types of bodies or loads. It can be placed on the lorry so the manipulator becomes part of it. The goal of the analysis is to investigate the drive forces in hydraulic cylinders which are necessary for the lifting of load with specified mass. The modern methods used computer aid with the special software for analysis processing, which can simulate not only the motion of the mechanism, but they can define the position, velocity, acceleration, forces, moments and other parameters in every moments of time, but verification and mechanics laws understanding are necessary. The results serve for dimensioning of hydraulic cylinders at the designing of mechanism.

Abstract: High-speed railway rolling bearings are tested on a special test rig, where large transit axial and radial load is applied. Design of loading structure and electro-hydraulic servo loading system are used in the rig to simulate the real operating conditions of the bearings. A segment control strategy using different control parameters in different conditions is presented in this paper, for reducing the gap effect when the direction of the axial load is changed. This method effectively reduces the load response time to meet the technical requirements of the test rig.

Abstract: Balancing the cost and processing precision of machine tool by the method of error allocation without affecting the machining performances is a critical problem in the Machine tool industry. In this paper, a new accuracy allocation method for multi-axis machine tool based on Multi-body system theory, manufacturing and quality loss costs and relationship between tolerances and accuracy parameters of components is proposed. This optimization method is performed with Non-Dominated Sorting Genetic Algorithm II algorithm using Isight and Matlab software. A three-axis vertical machine tool is taken as an example to demonstrate the method, and the optimization results show that the accuracy allocation method proposed is feasible in the optimization of geometric errors on the premise of satisfying machining accuracy requirements.

Abstract: Intelligent Manufacturing (IM) as a new model of mechanical manufacturing industry, attractting widely attention and research in the world. This paper based on the latest research progress of IM at home and abroad, from the key tecnnology, application field to their respective characteristics, stated the latest research results in the world, prospected the future direction of IM.

Abstract: HTHP rheology was investigated for the water-based drilling fluid applied in Yuanba region of Southwest Gas Fields in China. The results showed that under the conditions of temperature up to 180°C and pressure up to 100MPa, the Bingham plastic model is adequate to predict transient rheology at the given HTHP conditions. Effects of temperature on rheology are more dominant than that of pressure, but the latter will enhance at high temperatures and low shear rates. Finally, HTHP viscosity models were established and evaluated for water-based drilling fluid.