• Title, Summary, Keyword: Angle of inclination of ground

Search Result 53, Processing Time 0.046 seconds

Design of a Steering Control Mechanism for a Skateboard on Off-road Driving (비포장 노면 주행을 위한 스케이트보드의 조향제어기구 설계)

  • Sim Hansub
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.14 no.3
    • /
    • pp.110-115
    • /
    • 2005
  • Driving performance is affected by a steering mechanism and characteristics of the ground at off-road skateboarding. In order to drive on off-road, it is necessary off-road wheel and high performance steering mechanism to adapt on various configuration of the ground. In this paper, design factors are studied to affect to steering radius such as inclination angle of a king-bolt, distance of a wheel axle, and rolling angle of a deck plate. A steering system is adhered to inclination face of the deck plate. And, inclination angle is existed between the king-bolt and the flat face of the deck plate. Therefore, the wheel axle of the steering system can be steered by control of the rolling angle of the deck plate.

Development of an Algorithm for Compensating Ground Inclination to Expand an Operational Field of a Missile Launcher (발사플랫폼의 운용성 확장을 위한 지면기울기 보상기법)

  • Chung, Jae-Wook;Kim, Yong
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.15 no.1
    • /
    • pp.86-92
    • /
    • 2012
  • When missile is launched, a launcher needs to be leveled with accuracy to avoid the systems's instability. In general, a launcher is leveled by adjusting the stroke of leveling jacks; however, it is still challenge to control the leveling jacks fast and accurately. This paper thus proposed an innovative algorithm for compensating ground inclination of a missile launcher to expand operational field of a missile launcher. Using two inclinometers attached on a launcher, a base jack for leveling is selected and the mixed gradient where launcher stands on can be estimated. Due to the limited stroke, the launcher can compensate its ground inclination within maximum stroke margin. Then, the ground inclination of a launcher can be compensated by calculated angle using weighting factors. The effectiveness of proposed algorithm is proved with a prototype missile launcher.

A Study on the Rectangular-Shaped Passive Row Piles in Inclined Sand-Ground by Model Test (경사모래지반의 사각형 수동 열말뚝에 관한 실험적 연구)

  • Bae, Jong-Soon;Kim, Ji-Seong;Kwon, Min-Jae
    • Journal of the Korean Geotechnical Society
    • /
    • v.25 no.11
    • /
    • pp.39-51
    • /
    • 2009
  • This is a study on rectangular-shaped passive row piles in inclined sand-ground by model tests. The experiment controlled the angle of inclination of ground and induced the ground destruction. We also measured the behavior of row piles, by adjusting the shape, position and spacing of piles. As a result, we confirmed the earth pressure, the lateral resistance, and the effect of depressing on the ground variation working on passive pile. The effect of B-type pile of which the front width is wide is bigger than that of H-type pile of which the side width is wide. We can find out the failure angle of slope, the shared force of pile and soil by using the lateral resistance graph based on slope angle.

A Study of the Slim Design of Overhead Transmission Tower (가공송전철탑 경량화 설계에 관한 연구)

  • Lee, Jung-Won;Lee, Won-Kyo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.23 no.7
    • /
    • pp.560-565
    • /
    • 2010
  • This paper presents the design factor of an overhead transmission tower structure in order to reduce the tower weight. The behaviour of transmission tower structures are affected by the horizontal angle of the tower structure, the equivalent wind pressure group, the slope of the main post of the tower, the separation of the internode and the use of high-strength materials in their construction. Tower weight can be reduced by approximately 30% reduce weight by means of optimal design based on a consideration of all the above factors. In addition, the design of the foundation of the tower with the shear key installation to increase horizontal support together with a modified angle of inclination to the ground can reduce by about 37% the amount of concrete used during construction. The area of ground disturbed by the construction of the tower foundation can thus be reduced by approximately 33%. Therefore it is possible to build an environmently-friendly T/L tower with the mechanical properties of existing towers.

Numerical analysis of Flow Characteristic Around an Automobile with Variation of Slant Angle of Rear End (후미경사각 변화에 따른 자동차주위 유동특성 해석)

  • 정영래;강동민;박원규
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.9 no.1
    • /
    • pp.75-83
    • /
    • 2001
  • In this paper, numerical analysis is used to find the effects of inclination of rear end on flow characteristic around an automobile. The reference slant angle of rear end is 28.6$^{\circ}$, the slant angle of rear end is decreased to 24$^{\circ}$, 26.6$^{\circ}$ and also increased to 31.6$^{\circ}$, 36.4$^{\circ}$. The 3-D incompressible Navier-Stockes equations are solved by the iterative time marching scheme. The computed surface pressure coefficients were compared with experimental results and a good agreement has been achieved. The A- and C-pillar vortex and other flow phenomena around the ground vehicle are evidently shown. The variation of aerodynamic coefficients of drag, lift with respect to inclination angle of rear end are systematically studied. The flow characteristic on the automobile surface with respect to change of inclination of rear end have been also studied.

  • PDF

Improvement of the Tapering Error in the Centerless Through-feed Ground Parts Using a Work-rest Blade (공작물 받침대를 이용한 무심관통이송 공작물의 테이퍼링 오차 개선)

  • Kim, Kang
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.7
    • /
    • pp.70-77
    • /
    • 2003
  • The centerless through-feed grinding is performed by passing the workpiece between the grinding wheel and the regulating wheel. So, the amount of removed material around the leading end, of the workpiece is always more than that around the trailing end until the leading end leaves the grinding wheel. Because of this, there are differences in diameters along the workpiece axis during grinding, and workpiece axis is not parallel to the grinding wheel axis and the contact lines between the workpiece and wheels. Thus the ground workpiece shows tapering error inherently. To eliminate this error, the workpiece axis must be kept to be parallel to the grinding wheel axis. And, the direction of the workpiece axis can be controlled by the work-rest blade. Therefore, the effects of work-rest blade inclination angle on the through-feed centerless ground part are investigated in this study. As a result, it is found that there is a positive inclination angle of the work-rest blade for minimizing the tapering error of a ground workpiece.

Critical setback distance for a footing resting on slopes under seismic loading

  • Shukla, Rajesh Prasad;Jakka, Ravi S.
    • Geomechanics and Engineering
    • /
    • v.15 no.6
    • /
    • pp.1193-1205
    • /
    • 2018
  • A footing located on slopes possess relatively lower bearing capacity as compared to the footing located on the level ground. The bearing capacity further reduces under seismic loading. The adverse effect of slope inclination and seismic loading on bearing capacity can be minimized by proving sufficient setback distance. Though few earlier studies considered setback distance in their analysis, the range of considered setback distance was very narrow. No study has explored the critical setback distance. An attempt has been made in the present study to comprehensively investigate the effect of setback distance on footing under seismic loading conditions. The pseudo-static method has been incorporated to study the influence of seismic loading. The rate of decrease in seismic bearing capacity with slope inclination become more evident with the increase in embedment depth of footing and angle of shearing resistance of soil. The increase in bearing capacity with setback distance relative to level ground reduces with slope inclination, soil density, embedment depth of footing and seismic acceleration. The critical value of setback distance is found to increase with slope inclination, embedment depth of footing and density of soil. The critical setback distance in seismic case is found to be more than those observed in the static case. The failure mechanisms of footing under seismic loading is presented in detail. The statistical analysis was also performed to develop three equations to predict the critical setback distance, seismic bearing capacity factor ($N_{{\gamma}qs}$) and change in seismic bearing capacity (BCR) with slope geometry, footing depth and seismic loading.

Effect of the Earth Pressure Coefficient on the Support System in Jointed Rock Mass

  • Son, Moorak;Adedokun, Solomon;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
    • /
    • v.16 no.2
    • /
    • pp.33-43
    • /
    • 2015
  • This paper investigated the magnitude and distribution of earth pressure on the support system in jointed rock mass by considering different earth pressure coefficients, rock types and joint inclination angles. The study mainly focused on the effect of the earth pressure coefficients on the earth pressure. Based on a physical model test (Son & Park, 2014), extended studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the joints characteristics of rock mass. The results showed that the earth pressure was highly influenced by the earth pressure coefficients as well as the rock type and joint inclination angles. The effects of the earth pressure coefficients increased when the rock suffered more weathering and has no joint slide. The test results were also compared with Peck's earth pressure for soil ground, and clearly showed that the earth pressure in jointed rock mass can be greatly different from that in soil ground. This study indicated the earth pressure coefficients considering the rock types and joint inclination angles are important parameters influencing the magnitude and distribution of earth pressure, which should be considered when designing the support systems in jointed rock mass.

The Kinematic Analysis of the Lower Extremity Joint According to the Changes in Height of Box during Step Aerobics (스텝 에어로빅에서 박스 높이 변화에 따른 하지관절의 운동학적 분석)

  • Kim, Kyu-Soo;So, Jae-Moo;Kim, Yun-Ji;Yeo, Houng-Chul
    • Korean Journal of Sport Biomechanics
    • /
    • v.24 no.1
    • /
    • pp.67-74
    • /
    • 2014
  • This study researched into the left-right inclination of the rear foot at the lower limb joints, knee joint angle, angular velocity of the knee joint, angular acceleration and the max. Based on the analysis of kinematics according to the changes in the height of step box (6, 8, 10 inches) during step aerobics of female college students majoring in physical education. The findings of this study are as follows: Then angle of the knee joint decreased as the height of the step box increased the min. Angle was measured right before the right foot was on the step box, and the angle tended to decrease as the step box get heightened. The left-right inclination of the rearfoot angle according to the height of step box increased as the height increased. In the 'pull-up' stage during which the weight was loaded on the right foot the angle increased, while in the right foot stepping stage during which the right foot was on the ground, the left-right inclination of the rearfoot angle increased as the height of the step box increased. The angular velocity of the knee joint according to the height of step box started increasing when the right foot initially stepped on the step box and during the initial stepping section, the angular velocity decreased as the height of step box increased. The changes in angular acceleration of the knee joint according to the height of step box increased as the height of step box increased.

A Control Method of Driving a Paddy Vehicle Straight Ahead for Automatic Operation

  • Nagasaka, Yoshisada;Shigeta, Kazuto;Sato, Junichi
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • /
    • pp.1055-1062
    • /
    • 1996
  • A method for automatically driving paddy vehicles, such as rice transplanters, etc., straight ahead in a paddy field was investigated . The direction of such vehicles must be precisely controlled to do the operations as straight. However, the alignment of the from wheels becomes distorted due to the unevenness of the ground, preventing the vehicle form going straight. If the proper alignment of the front wheels is maintained , the vehicle can be driven straight ahead greater precision. To investigate the influence of the ground uneveness, the behavior of a paddy vehicle running over an obstacle was quantified. The left wheel ran over an obstacle on a flat concrete road surfaced. When the steering wheel was free, the front wheels were forced toward the left when vehicle went up the obstacle and toward the right when the vehicle went down it. The torsion of the wheel when the vehicle went down the obstacle was larger than that when it went up ,so it turned right 5 degrees. Sinc hydraulic control steering decreased the steering angle , it turned right 3 degrees. These results suggest that a vehicle can be driven straight ahead with high precision when the steering angle is changed in response to the direction and inclination of the vehicle . Such results were obtained in a paddy field tests.

  • PDF