Applied Mechanics and Materials Vols. 157-158

Abstract: Dynamic Mechanical Analysis (DMA) tests are carried out to investigate the viscoelastic deformation of Polycabonate (PC), Acrylonitrile-butadiene-styrene (ABS) and PC/ABS alloys with ratio of PC to ABS being 60/40, 50/50, 40/60, respectively. Storage and loss moduli of PC, ABS and PC/ABS alloys are measured from 0.01Hz to 200Hz at 95oC with DMA tests. The relaxation moduli of PC, ABS and PC/ABS alloys are tested from static tests and compared with those calculated from storage and loss moduli. Effect of ABS fraction on storage and loss moduli and relaxation modulus of PC/ABS alloys is also discussed.

Abstract: Edge tracing is considered important for deformable object manipulation in order to spread and reveal the original shape of an object before it can be sorted. This paper proposes a unique tracing method for t-shirt spreading by robots. Tracing in this paper context involves tracing the edge of the t-shirt, with the robot arm movement based on feedback from sensors. Adequate force control is also applied to the tracing gripper during tracing so that it doesn't grip the fabric too hard or vice versa which can affect the performance of the robot. Vision sensor is used from time to time to check whether the tracing gripper has reached a corner or not. Based on the algorithm used for towel spreading, algorithm for edge tracing of shirt to find a second or third corner is proposed. The method is simply looking at possibilities of tracing through corners, changing tracing trajectory as well as tracing on two layers of fabric. Practical experiments were conducted to evaluate the proposed method.

Abstract: A new type of bolt with wavy body has been designed for the supporting of burst prone rock masses and turned out to be a great success. To reveal its working mechanism, static and dynamic analyses have been carried out. Firstly, static pull-out investigations show that wavy body of the bolt has largely improved its deformation capability. Then, vibration modes and corresponding frequencies of wavy bolts and traditional point anchored bolts are obtained respectively by mode analyses. It is revealed that, at the same exciting frequency range, more vibration modes, especially the axial vibrations, can be excited for wavy bolts than for traditional bolts. Furthermore, Analyses on wave interaction between bolt and rock masses show that the energy catcher function of wavy bolt cluster is vital for its excellent supporting effect in burst prone rock masses.

Abstract: Owing to the problem of week strength, tripping and bad sealing of the hollow sucker rod joints, we designs a new sucker rod joint, which has two kinds of prototypes, including tapered shoulder and round shoulder. The hollow sucker rod’s characteristic is easy disassembling, multiple sealing, and also has a large contact area of the shoulder. By using the method of finite-element analysis, we set up the finite-element model and analyze the contact stress and deformation distribution of two kinds of structure in different friction coefficients. Through the analysis, we find not only the bearing capacity of the circular arc shoulder joint, but also the sealing is also better than the tapered shoulder's joint. And for both kinds of joints, the friction coefficient is an important factor to affect the pretightening force.

Abstract: Thin-walled structures exhibit complex nonlinear response under thermo-acoustic loadings. Complex stress-strain states decrease the fatigue life of structures seriously. Based on the thermo-acoustic response obtained, the rain flow cycle counting scheme is used to calculate the number of fatigue cycles. Then the Miner accumulative damage model is employed to predict high cycle fatigue life, combined with various nonzero mean stress models, including Morrow TFS, SWT. The nonlinear response and fatigue life of 2024-T3 aluminum plate are obtained under different combinations of thermo-acoustic loadings. Results show that the fatigue life of pre-buckled plate decreases with the increase of temperature. For post-buckled plate, as the temperature increases, the fatigue life of plate undergoing persistent snap-through keeps going down till the lowest, and then increases after entering intermittent snap-through regime. At high temperatures, the influence of high temperature on the S-N curve must be considered, the results may be erroneous otherwise.

Abstract: In this paper, the method of system dynamics is applied for the supply chain inventory management in FMCG industry. Based on the analysis of three-level supply chain inventory control loop, this paper establishes system dynamic models related profits and the service level of 2&3-level supply chain. After testing the validity of the model, the writer does some simulation through the system dynamics software Vensim．In addition, the model and simulation described in the paper are highly understandable and practicable, and thus have a very good prospect of application.

Abstract: This paper considers an SEIQS model with nonlinear incidence rate. By means of Lyapunov function and LaSalle’s invariant set theorem, we proved the global asymptotical stable results of the disease-free equilibrium. It is then obtained the sufficent conditions for the global stability of the endemic equilibrium by the compound matrix theory. In addition, we also study the phenomena of limit cycle of the systems with the numerical simulations.

Abstract: In this paper, energy consumption evaluation index system of the container terminal logistics system is briefly studied. Energy consumption is divided into two parts as dynamic and static energy consumption. Then an effective energy consumption evaluation model of container terminal logistics system is established.

Abstract: In order to make the decision-making of real estate more effectively, a model based on Projection Pursuit (PP) model was proposed. The PP model was employed to assessment the investment. And the model was used to the application of the decision-making of a real estate investment. The results are reasonable and verified with an example. This study provides a new method for the real estate investment.

Abstract: Influence of the Tabor parameter on the roughness-induced adhesion hysteresis was investigated. To achieve this, the adhesive contact model of single asperities was considered by incorporating the Maugis-dugdale model and its corresponding extension firstly. Further more, the load-approach relationship of adhesive contact between a rough surface and a flat was analyzed. The dissipation energy during a load and unload cycle is derived for general values of the Tabor parameter. It was found that the adhesion hysteresis becomes weaker gradually with the increase of the adhesion parameter, and it becomes stronger with the decrease of the Tabor parameter at the same adhesion parameter. The adhesion hysteresis for a special case that rough surfaces with DMT(Deryagin-Muller-Toporov)-type asperities is also discussed.