A Simulation Study on Warpage Analysis of Injection Moulded Plastic Part

A part to be injection molded is evaluated by simulation for warpage analysis. The plastic part is a supporting plate to be used in the oil filter and it’s made out of nylon material. The effect of various parameters from design to processing of plastic parts is considered and validated by simulation results. The research involved in this was designing mould, computer-aided engineering, simulation analysis, and determination of plastic part processing conditions. In this work PA66 (Grade name – Zytel 70G13HS1LNC010) material is used and the material contains 13 % of fiber. Fiber orientation is nothing but the distribution of plastic melt inside the cavity and it also plays important role in deciding the warpage of part. The effect of process parameters on part warpage is investigated from various aspects in comparison with the conventional runner system. Hot runner mould system with innovative cooling channel designs is good results-driven. Results of simulations reveal that elevated mould temperature reduces the unwanted freezing time during the injection phase and thus improves mouldability and enhances part quality. Under similar mould temperature conditions, the effect of process parameters on warpage decreases according to the following order, packing time, packing pressure, melt temperature, injection pressure, and cooling time respectively.

Analysis of the effect of various support distances to the bond-strength of plain anchor bolt in concrete

The structural components of reinforced concrete that withstand the tensile stress will be bonding stress affected by the friction between the reinforcing bar and the concrete. Anchoring depth, reinforcement diameter, and concrete quality are commonly assumed to influence bond strength; besides, the support distance of reinforcement may be one of the influencing factors. The samples in this study were cylindrical specimens with a diameter of 15 cm and 20 cm for the concrete compression strength and the bond-strength test, respectively, and double-L size 30 x 20 x 7.5 cm for the concrete shear test. Variables in this study include variations in the support distance represented by variations in the diameter of the supporting plate hole, namely 10 mm, 35 mm, 60 mm, 85 mm, and 110 mm. Plain reinforcement with a diameter of 10 mm was anchored at 150 mm depth in the centre of the concrete cylinder. The experimental results obtained 26.49 MPa and 10.86 MPa for concrete compression dan shear strength, respectively. Based on various diameters of the supporting plate hole, the hole diameter of 10 mm to 60 mm had a stable increase in bond strength and a significant decrease when a larger hole diameter was used.

Developing a Photoacoustic Whole-Breast Imaging System Based on the Synthetic Matrix Array

In this study, we reported a photoacoustic (PA) imaging system for whole-breast imaging. Similar to the traditional X-ray mammography, this system slightly compressed the breast by a water tank. The PA signal is acquired via scanning a long unfocused ultrasonic linear array probe over the breast top surface, and the expanded high-energy laser pulses illuminate the breast bottom through a transparent supporting plate. Scanning the unfocused transducer probe is equivalent to a synthetic two-dimensional (2D) matrix array, which significantly increased the field of view (FOV) via a much easier way and at a much lower cost. Our phantom results demonstrated that this system has a great potential for clinical implementation.

The Influence of Technological Parameters of the Plasma Spraying Process on the Macrostructure of Titanium Coatings

Capillary-porous surfaces are used in endoprosthetics as well as in catalytic converters and heat exchangers to increase the strength of adhesive bonding. Plasma spraying is one of the methods to obtain rough coatings for capillary-porous surfaces. Determining the relationships between the parameters of macrostructure of capillary-porous surfaces and the technological factors of the plasma spraying process enables one to control the surface characteristics. It is an important and fundamental element in the formation of the required properties of the surface. However, studies on the influence of technological parameters of plasma spraying on the construction and macrostructure of plasma-sprayed titanium surfaces are insufficient in scientific literature. This paper presents a study on the influence of roughness, curvature and the material of the supporting plate surface, as well as distance and angle of spraying on the structure of a VT1-0 titanium capillary porous coating applied to a VT6 titanium alloy supporting plate. A regression analysis of the experiment results is performed. It is shown that all the parameters have a significant influence on the surface structure. The experimentally obtained relationships make it possible to produce surfaces with required macrostructure parameters. They help to evaluate the possibility of obtaining titanium surfaces of this kind and thoroughly select parameters of the plasma spraying process in order to obtain surfaces with the required properties.

Development of a Dynamic Oriented Rehabilitative Integrated System (DORIS) and Preliminary Tests

Moving platforms were introduced in the field of the study of posturography since the 1970s. Commercial platforms have some limits: a limited number of degrees of freedom, pre-configured protocols, and, usually, they are expensive. In order to overcome these limits, we developed a robotic platform: Dynamic Oriented Rehabilitative Integrated System (DORIS). We aimed at realizing a versatile solution that can be applied both for research purposes but also for personalizing the training of equilibrium and gait. We reached these goals by means of a Stewart platform that was realized with linear actuators and a supporting plate. Each actuator is provided by an ad hoc built monoaxial load cell. Position control allows a large range of movements and load cells measure the reactive force applied by the subject. Transmission Control Protocol/Internet Protocol (TCP/IP) guarantees the communication between the platform and other systems. We integrated DORIS with a motion analysis system, an electromyography (EMG) system, and a virtual reality environment (VR). This integration and the custom design of the platform offer the opportunity to manipulate the available information of the subject under analysis, which uses visual, vestibular, and plantar feet pressure inputs. The full access to the human movements and to the dynamic interaction is a further benefit for the identification of innovative solutions for research and physical rehabilitation purposes in a field that is widely investigated but still open.

A Horizontal Azimuth Pattern-Reconfigurable Antenna Using Omnidirectional Microstrip Arrays for WLAN Application

A horizontal azimuth pattern-reconfigurable antenna with configurable parasitic element arrays for WLAN applications is proposed in this paper. It consists of a control board, a central series-fed omnidirectional microstrip array, four configurable parasitic elements, a bottom conducting plate, and a top supporting plate. The omnidirectional microstrip array is adopted as an exciter, around which the four same parasitic element arrays are arranged at four corners. The p-i-n diodes as switches are placed between the parasitic element arrays and the conducting plate to control the fifteen radiation patterns of the proposed antenna. The parasitic element arrays are configured as reflectors or directors by switching the p-i-n diodes on or off. The bandwidth achieved ranges from 5.00 GHz to 5.27 GHz. A gain of 8.52 dBi is obtained when the antenna reaches the maximum gain in the H-plane at 5.2 GHz. Good agreements between the simulated and measured results were observed. The proposed parasitic structure which has the same structure with the driven element can enhance the horizontal azimuth gain of the antenna. Only 4 p-i-n diodes are used to produce up to 15 useful beam configurations with a gain range of 4.56-8.52 dBi at the horizontal azimuth.