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Present paper aims to present the steps of developing a prototype used for the display of several functional parameters which does not normally appear on the dashboard of an automobile. Data is collected from the vehicle CAN bus, follow-up processed with a MCP2515 microcontroller and a ATMEGA328P and finally displayed on a color touchscreen. The prototype is a Plug&Play device, which can easily be connected to the vehicle’s OBD2 socket, from where the data is collected. The parameters are shown in an interactive manner, by displaying one or multiple parameters at a time, on a single page.

This paper presents experimental results from three-point bending tests for a composite made of quadriaxial glass fiber fabrics and an epoxy resin. Two composites were tested, one with 8 layers and the other with 16 layers; both had the same matrix (the epoxy resin). Tests were carried out, using five different test rates from 10 mm/min to 1000 mm/min. The following parameters were recorded and calculated: Young's modulus, flexural stress, flexural strain, energy, force, and all four for the first peak. The experimental data reveal no sensitivity for these materials based on the test rates, at least for the analyzed range; but, the characteristics for the thicker composite, with 16 layers of fabric, are slightly lower than those for the thinner composite, with 8 layers. The results pointed out that, for the same thickness of composite, certain characteristics, such as stress at the first peak, the flexural modulus, strain at the first peak, and energy at the first peak, are not sensitive to the test rate in the range 10–1000 mm/min. The energy at the first peak is double for the 16-layer composite compared to the 8-layer composite, but the specific energy (as energy on cross-sectional area) has close values: 103.47 kJ/m2 for the 8-layer composite and 106.51 kJ/m2 for the 16-layer composite. The results recommend this composite for applications in components with resistance to bending or for low-velocity impact protection. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of 3D amplitude and functional parameters for worn surfaces of composites with polyamide 6 as matrix and different glass bead concentrations (0%, 2.5%, 5%, 10%, 20%, 30% and 50%wt). The worn surfaces after dry sliding of a steel pin on a disk, for 10 km, at constant velocity (0.5 m/s, 1 m/s and 1.5 m/s) and under an average pressure of 1 MPa. There were done two tests under the same conditions. On each worn track, there were investigated three surfaces of 500 μm x 500 μm with a contact profilometer. The number of points on the scan line was 200 points and the step between lines was 5μm. The following amplitude parameters were measured and calculated for assessed surfaces: the arithmetic mean deviation, Sa, the root mean square deviation, Sq, the maximum height of surface prominence, Sp, the maximum surface depth, Sv, the maximum height, St, the skewness factor, Ssk and the kurtosis, Sku. The discussed functional parameters are the reduced peak height, Spk, the height of the core of the surface, Sk and the depth of the valley zone, Svk. The comparison of their values makes posible to evaluate if the worn surface could function in a new running or the replacement of the component is recommended. Considering that machine components have intermittent operation, these worn surfaces becoming initial surfaces for the following cycle of contact operation. Based on the average values of amplitude and functional parameters, it was found that a relatively good surface quality is preserved for concentrations of 10...30%wt glass beads, for v=0.5...1 m/s (Sa and Sq having similar trend); for lower concentrations and for 50% glass beads, the parameter values increase but without identifying a distinct relationship with the working regime, especially for 2.5 and 5% glass beads. [ABSTRACT FROM AUTHOR]

This paper presents an analysis based on experimental data for pointing out the behavior of rapeseed oil when it is additivated with a modifier of friction and wear, the nano hexagonal Boron nitride. All tests are done on a four-ball machine, in mild regime. Test parameters were sliding velocity (0.38 m/s, 0.53 m/s, 0.69 m/s, corresponding to the spindle rotational speed of the four-ball machine of 1000 rpm, 1400 rpm, 1800 rpm (±10 rpm),), force (100 N – 300 N), test duration 1 h. There were calculated the average friction coefficient during the test and the average wear scar diameter (WSD) for each test. The same test parameters were done twice and the values in this paper are the average of these two tests. Wear was discussed for the same velocity range, in terms of WSD, but for comparing tests with different sliding velocity (implicitly, different sliding distances), there was used the wear rate of the wear scar diameter. The results on wear parameters, using additivated rapeseed oil, do not show spectacular results for the parameters tested in this study, but underline the “insensitivity” of the lubricants to the variation of the test regime (especially with respect to sliding speed), which is desirable for certain applications. [ABSTRACT FROM AUTHOR]

This paper presents preliminary results and discussion on two aramid fabrics in order to establish their stab resistance when used as panels with different numbers of layers. Twaron fabrics SRM509 and CT736CMP, were arranged in 16 and 20 layers and in a combination of them (10 layers SRM509 and 10 layers CT736CMP). Samples of 130 mm x 130 mm were cut from the fabrics, weighed and measured for thickness. All tests were done for an impact energy of 24 J (the resulting impact velocity being 3 m/s). The blade had the geometry recommended in the standard Stab Resistance of Personal Body Armor NIJ Standard-0115.00 as P1. The conclusion of this analysis is that the better behavior to stab is obtained for panels that have higher gradients in time, for all four characteristics here discussed: force, displacement, absorbed energy and velocity. When using hybrid panels, the results could intermediate those of the components, this solution could be recommended for reasons as price, weight. [ABSTRACT FROM AUTHOR]

This paper presents a macro FEM isothermal model for simulating the impact of a 9 mm FMJ bullet on a stratified packs in order to restrain the preliminary tests for actual stratified packs made of layers of Twaron LFT SB1plus (Teijin), taking into account the friction between layers and between bullet and layers, in order to obtain the number of layers that arrest the bullet. The layers were considered as an orthotropic material, with maximum equivalent plastic strain of 0.06. The materials are modeled as bilinear isotropic with hardening. The analyzed parameter to validate the model was the number of broken layers. The average value of back face signature for a 12 layer pack was of 19.44 mm recommending it for protection level of II and IIA (NIJ Standard-0101.06-2008).

Vegetable oil-based lubricants have several disadvantages as compared to mineral and synthetic ones, including low viscosity that not encourage the generation of a continuous film when the tribosystem runs, consequently, implying a mixt or boundary. This is why the additivation of such oils is of great interests for researchers, producers and users. This paper presents results of testing the soybean oil additivated with nano graphite (0.25%wt, 0.50%wt and 1%wt) on a four ball machine. The friction coefficient is slightly increased for the additivated lubricants, but no evident dependency on concentration and test conditions was noticed. Supplementary tests will give the opportunity of a statistical approach of this parameter. Any concentration of nano graphite makes the wear parameter (wear scar diameter) to slightly increase as compared to the values obtained for the non-additivated soybean oil. The increase of the nano graphite concentration in this vegetable oil does not influence significantly the wear parameter, meaning that, at least for the tested regime, this is not an efficient anti-wear additive.

This paper compares two models for ballistic impact on unidirectional fabrics in order to evaluate their influence in making the simulation closer to actual events. The importance of including the effect of fibers and yarns architecture, their properties and those for their matrix in the model is highlighted by figures showing equivalent stress distributions at different moments of the impact and images from the run simulations. It resulted that the model with interlaminar delamination is more suitable for these simulations considering the stress distribution analyzed for the main yarns of the panel. [ABSTRACT FROM AUTHOR]

This paper presents and analysis of several 3D amplitude parameters of the texture, measured or calculated for the entire wear scar of the stationary balls used in four-ball tester: Sa, St, Sv, Sp, Ssk and Sku. The authors investigated balls tested in rapeseed oil, rapeseed oil + 1% TiO2 and rapeseed oil +1 % ZnO in order to establish the influence of the testing regime (sliding velocity and force on the main shaft of the tester) on the surface quality at the end of the test, by the help of several amplitude 3D parameters. Qualitatively, the wear process is uniform on the balls in one test, because spread ranges of the discussed parameters are small enough. At low force (F=100 N), corroborating the values of the studied amplitude parameters, it could be concluded that wear processes take place on the peaks of the texture. The Sa parameter is not affected by additivation for v=0.38 m/s and forces from F=100 N to F=300 N. At high sliding velocity, a slope change of both parameters is observed between F=200 N and F=300 N. If the wear is approximately the same at the test end for F=300 N, the roughness of the wear trace increases greatly when the rapessed oil is additivated with, meaning that nano particle of TiO2 agglomerate and participate in the formation of a rougher texture. Lubricant with ZnO keeps the average roughness Sa close to that obtained with nonadditivated rapeseed oil. In order to assess the quality of a surface as close as possible to reality, using 3D parameters, the profilometer pitch should be as fine as possible and the area of investigation as large as possible. However, a trade-off has to be done between the step size, the investigation area and, of course, time to fulfill the study. The Sku parameter shows if there are large isolated peaks and Ssk indicates if the peak frequency is high. For the case of worn surfaces, it is the values of the parameters Ssk, Sku, St, Sp and Sv that are of interest, because high peaks affect the tribological parameters. The surface quality when additivated with 1% TiO2 is much better up to F=300 N. Additivation with 1% TiO2 is recommended for low loads, F=100 N and F=200 N, for point contacts. Study should be completed with the same investigation in severe regime where nano-additives should improve seizure limit of load. [ABSTRACT FROM AUTHOR]