scholarly journals Comprehensive Analysis of Minibuses Gravity Center: A Post-Production Review for Car Body Industry

2021 ◽  
Vol 1 (1) ◽  
pp. 31-40
Author(s):  
Djoko Wahyu Karmiadji ◽  
Muchamad Gozali ◽  
Muji Setiyo ◽  
Thirunavukkarasu Raja ◽  
Tuessi Ari Purnomo
Keyword(s):  
Traffic Safety ◽  
Load Transfer ◽  
Mining Area ◽  
Front Wheel ◽  
Test Results ◽  
Gravity Center ◽  
Fundamental Parameters ◽  
Car Body ◽  
Test Objects

The center of gravity (CoG) on the minibus is one of the fundamental parameters that affect the operation of the vehicle to maintain traffic safety. CoG greatly affects vehicle maneuverability due to load transfer between the front and rear wheels, such as when turning, braking, and accelerating. Therefore, this research was conducted to evaluate the operational safety of minibusses produced by the domestic car body industry. The case study was conducted on a minibus with a capacity of 30 passengers to be used in a mining area. Investigations on CoG were carried out based on the minibus specification data, especially the dimensions and forces acting on the wheels. Minibusses as test objects were categorized in two conditions, namely without passengers and with 30 passengers. The test results are expressed in a coordinate system (x, y, z) which represents the longitudinal, lateral, and vertical distances to the center of the front wheel axle. CoG coordinate values ​​without passengers are (2194.92; 7.11; 1327.97) mm and CoG coordinates with full passengers (30 people) are (2388.52; 13.04; 1251.72) mm. The test results show that the change in CoG at full load is not significant which indicates the minibus is safe when maneuvering under normal conditions.

scholarly journals Case Study on the Mechanism of Influence of Stoppage on Ground Pressure under Different Rates of Advance

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiaoxu Gao ◽  
Xinyu Shi ◽  
Weibin Guo
Keyword(s):  
Load Transfer ◽  
Mining Area ◽  
Ground Pressure ◽  
Working Face ◽  
Force Majeure ◽  
Rate Of Increase ◽  
Coal Wall ◽  
Two Stages ◽  
Roof Falling

Because of daily maintenance, equipment damage, gas overrun, and other force majeure factors, the continuous stopping of the working face causes the roof pressure to accumulate, which leads to causing accidents such as coal wall spalling and roof falling. To address the roof safety problem caused by continuous stoppages, the 620 working face in the Huangling mining area is taken as the research object. Through field measurement, theoretical analysis, numerical simulation, and other research methods, the influence and mechanism of stopping pressure under different rates of advance are studied. The results show that the velocity factor of roof load transfer is positively correlated with the advancing velocity of the working face; the reasonable length of the suspended roof is mainly affected by the number of caving holes and the effect of pressure relief; and comparing the two stages of advance speed of 4.8 m/d and 12.8 m/d, the periodic weighting step distance of the latter increases by 24.4% compared with the former, and the rate of increase of support load caused by stopping mining increases by 42.1% compared with the former. The roof pressure accumulation caused by stopping mining is increased. Taking appropriate measures for local forced caving of the working face can release the roof pressure and reduce the risk of local caving of the working face. The study can provide a theoretical basis for roof control of continuous stopping under similar engineering conditions.

Simplified 7 DOF Model of Car Vertical Vibrations for Small Pitch and Roll Angles

2015 ◽  
Vol 801 ◽  
pp. 136-141
Author(s):  
Dan N. Dumitriu ◽  
Veturia Chiroiu ◽  
Ligia Munteanu
Keyword(s):  
Vertical Displacement ◽  
Dynamics Model ◽  
Gravity Center ◽  
Car Body ◽  
Road Profile ◽  
Small Pitch ◽  
Vertical Displacements ◽  
Vertical Vibrations ◽  
Good Agreement

This paper concerns a simplified 7 DOF model for car vertical vibrations. The classical 7 DOF of the considered 3D vertical model are: the vertical displacement of the gravity center of the car body, the roll and pitch angles of the car body and the four vertical displacements of the wheels centers. Using the x-y-z sequence of rotations parameterization, the Euler’s rotation equations concerning the roll and pitch angle are easily obtained. Small differences are observed between our car body rotation equations concerning the two pitch and roll angles and the same equations provided by Demić et al. [6]. For small pitch and roll angles, no differences were observed with respect with [6]. Also, no differences were observed concerning the other 5 dynamics equations of the 7 DOF model, the ones for the vertical displacements.The simplified 7 DOF car vertical dynamics model, comprising two rotation equations (for pitch and roll angles) and five dynamics equations concerning vertical displacements/accelerations, were integrated/simulated in Matlab. For small pitch and roll angles (a rather flat and smooth straight road profile was considered in our case study), the results obtained using the in-house 7 DOF model Matlab simulator are in very good agreement with the results provided by CARSIM.

PENGKAJIAN KEKUATAN BETON STRUKTUR JEMBATAN PASCA KEBAKARAN

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Strength Assessment ◽  
Concrete Testing

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.

Rancang Bangun Piranti Lunak Pengolah Data Pasca Pengujian Terowongan Angin Kecepatan Rendah Indonesia

2016 ◽  
Vol 7 (2) ◽  
pp. 131-138
Author(s):  
Ivransa Zuhdi Pane
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Effective Solution ◽  
Post Processing ◽  
Prototype Development ◽  
Design Activities ◽  
Index Terms ◽  
Test Objects ◽  
Processing Requirement

Data post-processing plays important roles in a wind tunnel test, especially in supporting the validation of the test results and further data analysis related to the design activities of the test objects. One effective solution to carry out the data post-processing in an automated productive manner, and thus eliminate the cumbersome conventional manual way, is building a software which is able to execute calculations and have abilities in presenting and analyzing the data in accordance with the post-processing requirement. Through several prototype development cycles, this work attempts to engineer and realize such software to enhance the overall wind tunnel test activities. Index Terms—software engineering, wind tunnel test, data post-processing, prototype, pseudocode

scholarly journals The Problem of Carbon Dioxide Emissions from Closed Coal Mine Shafts – The Overview and the Case Study

2016 ◽  
Vol 61 (3) ◽  
pp. 587-600
Author(s):  
Paweł Wrona ◽  
Józef Sułkowski ◽  
Zenon Różański ◽  
Grzegorz Pach
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Carbon Dioxide Emission ◽  
Mining Area ◽  
Emission Point ◽  
Water Pumping ◽  
Gas Hazard ◽  
Flow Through ◽  
Reporting Procedures

Abstract Greenhouse gas emissions are a common problem noticed in every mining area just after mine closures. However, there could be a significant local gas hazard for people with continuous (but variable) emission of these gases into the atmosphere. In the Upper Silesia area, there are 24 shafts left for water pumping purposes and gases can flow through them hydraulically. One of them – Gliwice II shaft – was selected for inspection. Carbon dioxide emission with no methane was detected here. Changes in emission and concentration of carbon dioxide around the shaft was the aim of research carried out. It was stated that a selected shaft can create two kinds of gas problems. The first relates to CO2 emission into the atmosphere. Possible emission of that gas during one minute was estimated at 5,11 kg CO2/min. The second problem refers to the local hazard at the surface. The emission was detected within a radius of 8m from the emission point at the level 1m above the ground. These kinds of matters should be subject to regular gas monitoring and reporting procedures.

scholarly journals Null-Result Test for Effect on Weight from Large Electrostatic Charge

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 160-172
Author(s):  
G. Hathaway ◽  
L. L. Williams
Keyword(s):  
Scalar Field ◽  
Long Range ◽  
Buoyancy Force ◽  
Weak Field ◽  
Electrostatic Charge ◽  
Measurement Precision ◽  
Test Results ◽  
Static Test ◽  
Null Result ◽  
Test Objects

We report test results searching for an effect of electrostatic charge on weight. For conducting test objects of mass of order 1 kg, we found no effect on weight, for potentials ranging from 10 V to 200 kV, corresponding to charge states ranging from 10−9 to over 10−5 coulombs, and for both polarities, to within a measurement precision of 2 g. While such a result may not be unexpected, this is the first unipolar, high-voltage, meter-scale, static test for electro-gravitic effects reported in the literature. Our investigation was motivated by the search for possible coupling to a long-range scalar field that could surround the planet, yet go otherwise undetected. The large buoyancy force predicted within the classical Kaluza theory involving a long-range scalar field is falsified by our results, and this appears to be the first such experimental test of the classical Kaluza theory in the weak field regime, where it was otherwise thought identical with known physics. A parameterization is suggested to organize the variety of electro-gravitic experiment designs.

scholarly journals Plantar load transfer in children: a descriptive study with two pathological case studies

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Alexis Brierty ◽  
Christopher P. Carty ◽  
Claudia Giacomozzi ◽  
Teresa Phillips ◽  
Henry P. J. Walsh ◽  
...  
Keyword(s):  
Case Studies ◽  
Load Transfer ◽  
Descriptive Study ◽  
Transfer Phase ◽  
Gait Symmetry ◽  
Plantar Pressures ◽  
Gait Asymmetry ◽  
Mean Pressure ◽  
Pathological Case

Abstract Background Typical gait is often considered to be highly symmetrical, with gait asymmetries typically associated with pathological gait. Whilst gait symmetry is often expressed in symmetry ratios, measures of symmetry do not provide insight into how these asymmetries affect gait variables. To fully understand changes caused by gait asymmetry, we must first develop a normative database for comparison. Therefore, the aim of this study was to describe normative reference values of regional plantar load and present comparisons with two pathological case studies. Methods A descriptive study of the load transfer of plantar pressures in typically developed children was conducted to develop a baseline for comparison of the effects of gait asymmetry in paediatric clinical populations. Plantar load and 3D kinematic data was collected for 17 typically developed participants with a mean age of 9.4 ± 4.0 years. Two case studies were also included; a 10-year-old male with clubfoot and an 8-year-old female with a flatfoot deformity. Data was analysed using a kinematics-pressure integration technique for anatomical masking into 5 regions of interest; medial and lateral forefoot, midfoot, and medial and lateral hindfoot. Results Clear differences between the two case studies and the typical dataset were seen for the load transfer phase of gait. For case study one, lateral bias was seen in the forefoot of the trailing foot across all variables, as well as increases in contact area, force and mean pressure in the lateral hindfoot of the leading foot. For case study two, the forefoot of the trailing foot produced results very similar to the typical dataset across all variables. In the hindfoot of the leading foot, medial bias presents most notably in the force and mean pressure graphs. Conclusions This study highlights the clinical significance of the load transfer phase of gait, providing meaningful information for intervention planning.

Motorcyclists' Brake Operation, Motorcycle Brake Controls and a Case Study: The Need for Human Factors Engineering

2002 ◽  
Vol 46 (10) ◽  
pp. 890-894 ◽  
Author(s):  
Rudolf G. Mortimer
Keyword(s):  
Human Factors ◽  
Front Wheel ◽  
Human Factors Engineering ◽  
Braking Performance ◽  
Wheel Brake

A survey was made of the braking techniques reportedly used by 180 motorcyclists in a variety of conditions. Overall, the motorcyclists indicated that they used both front and rear brakes in hard braking 75% of the time on dry pavement and 47% on wet, but in other conditions they mostly used the rear brake first or exclusively. That the rear brake is preferred is not surprising because of the design of the brake controls and other reasons. Reliance on the rear brake at the expense of the front wheel brake leads to reduced deceleration. A crash case study exemplifies the effect. Integrated brakes, in which each brake control simultaneously activates the brakes on the front and rear wheels, are indicated by good human factors design and by motorcyclist's braking performance and should improve safety, especially when the brakes incorporate anti-locking mechanisms

Drive and Brake Joint Control of Acceleration Slip Regulation Road Test

2014 ◽  
Vol 971-973 ◽  
pp. 454-457
Author(s):  
Gang He ◽  
Li Qiang Jin
Keyword(s):  
Front Wheel ◽  
Driving Ability ◽  
Joint Control ◽  
Test Results ◽  
Road Test ◽  
Wheel Slip ◽  
Traction Control ◽  
Wheel Drive ◽  
Driving Wheel ◽  
Independent Design

Based on the independent design front wheel drive vehicle traction control system (TCS), we finished the two kinds of working condition winter low adhesion real vehicle road test, including homogenous pavement and separate pavement straight accelerate, respectively completed the contrastive experiment with TCS and without TCS. Test results show that based on driver (AMR) and brake (BMR) joint control ASR system worked reliably, controlled effectively, being able to control excessive driving wheel slip in time, effectively improved the driving ability and handling stability of vehicle.

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