• Title/Summary/Keyword: shear force variation

Search Result 119, Processing Time 0.033 seconds

A Study on the Change of Tensile Force of Friction Type Anchor under Shear Deformation of Ground (지반의 전단변형에 따른 마찰형 앵커의 긴장력 변화에 대한 연구)

  • You, Min-Ku;Kwon, O-Il;Lee, Sang-Duk
    • Journal of the Korean Geotechnical Society
    • /
    • v.34 no.4
    • /
    • pp.13-25
    • /
    • 2018
  • When deformation occurs on slope reinforced with anchor, shear stress and bending stress are applied on the shear surface along the slip surface and increase of the shear deformation causes the tension force variation of the anchor. In this study, shear test was performed by measuring the tension force of the anchor by inducing shear deformation in vertical direction of the anchor using a large-scale direct shear test equipment in order to confirm the tension force variation of the anchor induced by shear deformation. The shear test was performed for 8 conditions which were classified according to the anchor reinforcement, separation distance (1D, 2D, 4D) from the shear surface to bonded part and the lateral-pressure condition (0.1 MPa, 0.2 MPa) of adjacent ground. As a result of the shear test, it was found that the separation distance and the lateral-pressure condition affect the shear force of the ground reinforced by anchor and the tension force of the anchor, and experimentally verified that the shear force variation is related to axial force variation of the anchor head and tip. Therefore, it was confirmed that the behavior of the bonded part induced by the shear deformation can be indirectly predicted by analyzing the tendency of the tension force variation of the anchor head.

Inelastic seismic analysis of RC bridge piers including flexure-shear-axial interaction

  • Lee, Do Hyung;Elnashai, Amr S.
    • Structural Engineering and Mechanics
    • /
    • v.13 no.3
    • /
    • pp.241-260
    • /
    • 2002
  • The effect of shear coupled with axial force variation on the inelastic seismic behaviour of reinforced concrete bridge piers is investigated in this paper. For this purpose, a hysteretic axial-shear interaction model was developed and implemented in a nonlinear finite element analysis program. Thus, flexure-shear-axial interaction is simulated under variable amplitude reversed actions. Comparative studies for shear-dominated reinforced concrete columns indicated that a conventional FE model based on flexure-axial interaction only gave wholly inadequate results and was therefore incapable of predicting the behaviour of such members. Analysis of a reinforced concrete bridge damaged during the Northridge (California 1994) earthquake demonstrated the importance of shear modelling. The contribution of shear deformation to total displacement was considerable, leading to increased ductility demand. Moreover, the effect of shear with axial force variation can significantly affect strength, stiffness and energy dissipation capacity of reinforced concrete members. It is concluded that flexure-shear-axial interaction should be taken into account in assessing the behaviour of reinforced concrete bridge columns, especially in the presence of high vertical ground motion.

A Study on the Dynamic Stability of a Flexible Missile with Mass Variation (질량변화를 갖는 유연한 미사일의 동적 안정성에 관한 연구)

  • Ryu, Bong-Jo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.8 no.4
    • /
    • pp.107-117
    • /
    • 1991
  • The dynamic stability problem of nonconservative system is one of the important problems. In this study, flexible missile with mass variation is regarded as a free Timoshenko beam subjected to a controlled follower force. The stability was studied numerically through the finite element method. Through the study, the obtained results are as follows: [1] Without force direction control (1) In the case of no mass reduction, the existence of concentrated mass increases critical follower force. (2) Mass reduction rate of the beam slightly effects on the change of critical follower force. [2] With force direction control (1) Shear deformation parameter S contributes insignificantly to the force at instability when $S{\geq}10^4$. (2) With mass variation, increase of concentrated mass increases critical follower force at instbility. (3) The type of promary instability is determined by the sensor location.

  • PDF

An Experimental Study on the Fatigue Behavior of Torque Shear Type High Tension Bolted Joints (Torque Shear형 고장력 볼트 이음부의 피로거동에 관한 실험적 연구)

  • CHANG, Dong Il;Lee, Sung Uk
    • Journal of Korean Society of Steel Construction
    • /
    • v.8 no.3 s.28
    • /
    • pp.151-160
    • /
    • 1996
  • The fatigue test under the constant amplitude repeated loading is performed to investigate the fatigue behavior of the Torque Shear type high tension bolted joint which is able to manage the axial force uniformly. From the test results, it's known that the reduction of the axial force of T/S bolt followed by the elasped time is similar to that of the high tension bolts. The difference of relaxation is not occurred according to the position of bolts, the size of the introduced axial force but the effect of the variation of temperature is large. In the reduction of the axial force followed by the cumulation of the fatigue load, the outer bolt is larger than the inner bolt. This result depends on the difference in the distribution of the non-slip zone. The variation of the surface roughness affects the slip and the reduction of the anal force.

  • PDF

Estimation of Sensory Pork Loin Tenderness Using Warner-Bratzler Shear Force and Texture Profile Analysis Measurements

  • Choe, Jee-Hwan;Choi, Mi-Hee;Rhee, Min-Suk;Kim, Byoung-Chul
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.29 no.7
    • /
    • pp.1029-1036
    • /
    • 2016
  • This study investigated the degree to which instrumental measurements explain the variation in pork loin tenderness as assessed by the sensory evaluation of trained panelists. Warner-Bratzler shear force (WBS) had a significant relationship with the sensory tenderness variables, such as softness, initial tenderness, chewiness, and rate of breakdown. In a regression analysis, WBS could account variations in these sensory variables, though only to a limited proportion of variation. On the other hand, three parameters from texture profile analysis (TPA)-hardness, gumminess, and chewiness-were significantly correlated with all sensory evaluation variables. In particular, from the result of stepwise regression analysis, TPA hardness alone explained over 15% of variation in all sensory evaluation variables, with the exception of perceptible residue. Based on these results, TPA analysis was found to be better than WBS measurement, with the TPA parameter hardness likely to prove particularly useful, in terms of predicting pork loin tenderness as rated by trained panelists. However, sensory evaluation should be conducted to investigate practical pork tenderness perceived by consumer, because both instrumental measurements could explain only a small portion (less than 20%) of the variability in sensory evaluation.

Shear Strength Prediction of Reinforced Concrete Members Subjected In Axial force using Transformation Angle Truss Model (변환각 트러스 모델에 의한 축력을 받는 철근콘크리트 부재의 전단강도 예측)

  • Kim Sang-Woo;Lee Jung-Yoon
    • Journal of the Korea Concrete Institute
    • /
    • v.16 no.6 s.84
    • /
    • pp.813-822
    • /
    • 2004
  • For the prediction of the shear strength of reinforced concrete members subjected to axial force, this paper presents a truss model, Transformation Angle Truss Model (TATM), that can predict the shear behavior of reinforced concrete members subjected to combined actions of shear, axial force, and bending moment. In TATM, as axial compressive stress increases, crack angle decreases and concrete contribution due to the shear resistance of concrete along the crack direction increases in order to consider the effect of the axial force. To verify if the prediction results of TATM have an accuracy and reliability for the shear strength of reinforced concrete members subjected to axial forces, the shear test results of a total of 67 RC members subjected to axial force reported in the technical literatures were collected and compared with TATM and existing analytical models(MCFT RA-STM and FA-STM). As a result of comparing with experimental and theoretical results, the test results was better predicted by TATM with 0.94 in average value of $\tau_{test}/\tau_{ana}$. and $11.2\%$ in coefficient of variation than other truss models. And theoretical results obtained from TATM were not effect by steel capacity ratio, axial force, shear span-to-depth ratio, and compressive steel ratio.

A Study on the Secure Plan of Clamping Force according to the Variation of Torque-Coefficient in Torque-Shear High Strength Bolts (토크전단형 고력볼트의 토크계수 변동에 따른 체결축력 확보방안에 관한 연구)

  • Lee, Hyeon-Ju;Nah, Hwan-Seon;Choi, Sung-Mo
    • Journal of the Korean Society for Advanced Composite Structures
    • /
    • v.5 no.3
    • /
    • pp.8-16
    • /
    • 2014
  • Torque control method and turn of nut method are specified as clamping method of high strength bolts in the steel construction specifications. Quality control of torque coefficient is essential activity because torque control method, which is presently adopted as clamping method in domestic construction sites, is affected by variation of torque coefficient. The clamping of torque shear bolt is based on KS B 2819. It was misunderstood that the tension force of the TS bolt was induced generally at the break of pin-tail specified. However, the clamping forces on slip critical connections do not often meet the intended tension, as it considerably varies due to torque coefficient dependent on the environmental factors and temperature variables despite the break of the pin tail.This study was focused to evaluate the effect of environmental factors and errors of installing bolts during tightening high strength bolts. The environmental parameters were composed of 'wet' condition, 'rust' condition, 'only exposure to air' condition. And the manufacture of trial product was planned to identify the induced force into the bolts. The algorithm for a trial product was composed of the relation between electricity energy taken from torque shear wrench and tension force from hydraulic tension meter.

Effects of Linear and Nonlinear Shear Deformation on Measurement for Stickiness of Cosmetics Using Rotational Rheometer

  • Bae, Jung-Eun;Ryoo, Joo-Yeon;Kang, Nae-Gyu
    • Korea Journal of Cosmetic Science
    • /
    • v.2 no.1
    • /
    • pp.33-46
    • /
    • 2020
  • Cosmetics are representative complex fluids, and there have been many studies focusing on the correlation between the rheological properties and sensory attributes. Various instrumental measurements have been suggested to evaluate the sensory attributes, and one of the most common instruments is Texture Analyzer (TA). Although it is reported that the adhesiveness measured by TA is related to the stickiness of cosmetics, there exists reproducibility problem because measurements with TA are sensitive to application conditions. In this study, an instrumental protocol using rotational rheometer has been set up to measure the stickiness of cosmetics. This protocol consists of two steps. The first step is a preconditioning step, and various types of shear deformations are applied to the samples. The next step is the extensional flow and the axial force is measured. When the amplitude of the shear flow corresponded to the linear viscoelastic region, the axial force is the same as those without preconditioning. On the other hand, an axial force decreases as variation nonlinearity increases. It is because the effects of microstructure changes caused by nonlinear deformation affects the extensional flow. It is worth noting that a new protocol facilitates to evaluate the stickiness of cosmetics in a more systematic way.

Shear Force Variation of Stiffening Girder caused by Vibration of Stay Cable (사장 케이블 진동에 의한 보강형의 전단력 변화)

  • Kim, Hyeon Kyeom;Hwang, Jae Woong;Lee, Myeong Jae
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.1A
    • /
    • pp.1-8
    • /
    • 2009
  • Stay cable is easily exposed to vibration induced rainy wind effects. There are some problems for not only unexpected vibration but also well-known vibration. An outbreak of displacement by the said effects brings damages such as over-tension of cables and barriers, fatigue of anchorages and dampers, and additional shear force variation of stiffening girders. This study suggests analytic methodology for dynamic tension variation of cables and shear force variation of stiffening girders. Additionally this study announces with dynamic problems for cable stayed bridge briefly. To realize this subject, we divide restoring force into chord component and normal component and then make up the differential equations which can satisfy physical phenomenon for each component. Finally we apply adequate functions such as sinusoidal and parabola in order to reduce these differential equations. Therefore we can meet with good results through a series of above process. As a remarkable result, CIP recommendations (2002) give inadequate solution with over 10% error. However it gives very good solution if parts of our study are reflected at the said recommendations. The fact means that CIP recommendations (2002) well-known as international standard of stay cables are not even concern about this subject yet. For verification of this study, F.E. analysis using E.C.C. with external forces was fulfilled, and the accuracy and conciseness of this study were shown.

Flow Routing in Prismatic Symmetrical Compound Channels by Applications of the Apparent Shear Force (ASF)

  • Chun, Moo-Kap;Jee, Hong-Kee
    • Korean Journal of Hydrosciences
    • /
    • v.8
    • /
    • pp.41-56
    • /
    • 1997
  • A new routing computer model for the symmetric compound channel called the ASRMCS(Apparent Shear Force Muskingum-Cunge Method in Symmetry) has been developed. The Muskingum-Cunge routing method is adapted. The Apparent Shear Force (ASF) between the deep main channel and the shallow floodplan flow is introduced while the flow is routed. The nonlinear parameter method is applied. The temporal and spatial increments are varied according to the flow rate. The adaptation of above schemes is tested against the routed hydrographs using the DAMBRK model. The results of general routing practice of Muskingum-Cunge Method(GPMC) are also compared with those of above two models. The results of the new model match remarkably well with those of DAMBRK. The routed hydrographs show a smooth variation from the inflow boundary condition without any distortions caused by the difference of cross-section shape. However, the results of GPMC, showing early rise and fall of routed hydrograph, have considerable differences from those of the ASFMCS and DAMBRK.

  • PDF