• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.44.3-44
• /
• 2001

This articles describes a novel design elastic joint manipulator for a mobile robot, which works in an office environment with humans. The primary goal of this manipulator design is safeness on collision and contact. To achieve this, each joint is made of an elastic element and this is driver with a high ratio gear tram. The performance was verified, however, it has a serious drawback. It produce vibration, due to the elastic joints and high ratio gear train. We found that a sliding mode controller has an excellent performance for reducing such vibration. Results of computer simulation and experiments are shown.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
• /
• pp.337-344
• /
• 2001

This paper is concerned with the change of joint rigidity in estimating the degree of semi-rigidity of connections and the buckling load in a single layer latticed dome. The estimations are based on information about the ratio for the rotational stiffness of the connection to the flexural stiffness of the member and the minimum eigenvalue of a structure for pinned, semi-rigid and completely rigid cases, respectively. Connection characteristics are reflected in the ratio control of joint rigidity for the DOFs to be related using the spring element by FEM.

• 대한조선학회지
• /
• 제18권4호
• /
• pp.21-29
• /
• 1981

In this paper, plastic behavior and plastic strength of cruciform fillet welded joint under tension is investigated by finite element method. Attension is focussed, in particular, on the effect of geometry of fillet weld including its contour, size and penetration. And the approximate analysis of welded joint have been carried out from a simple model constructed by three zone, ie, base metal, heat affected zone, and weld metal.

• 한국지반환경공학회 논문집
• /
• 제17권1호
• /
• pp.29-37
• /
• 2016

This study examined the magnitude and distribution of earth pressure on the support system in a jointed rock mass due to the different joint spacing as well as varying the rock type and joint condition (joint shear strength and joint inclination angle). Based on a physical model test and its numerical simulation, a series of numerical parametric analyses were conducted using a discrete element method. The results showed that the magnitude and distribution of earth pressure were strongly affected by the different joint spacing as well as the rock type and joint condition. In addition, the study results were compared with Peck's earth pressure for soil ground, which indicated that the earth pressure in a jointed rock mass could be considerably different from that in soil ground. The study suggests that the joint spacing as well as the rock type and joint condition are important factors affecting the earth pressure in a jointed rock mass and they should be considered when designing a support system in a jointed rock mass.

• 한국자동차공학회논문집
• /
• 제21권2호
• /
• pp.154-158
• /
• 2013

Expansion joint has been utilized in many areas including automotive bellows for exhaust system. Usage of expansion joint has been increased due to its inherent flexibility and excellent anti-vibration property. Simple shape of expansion joint is modeled to understand the behavior of joint system. 27 design cases using 3 design factors with 3 levels are constructed by design of experiment. Each case is simulated to find the most influential design factors. Response for this study, maximum stress in the expansion joint, has been used to determine main design factors of joint. Among the 3 design factors, factor B has affected greatly a response in the formation of optimum shape of joint. Also, interaction factor, $A{\times}B$, has also showed its influence to the response of joint. This study showed that design of experiment combined with finite element analysis could be used in the design decision process effectively in the design of expansion joint.

• Structural Engineering and Mechanics
• /
• 제77권4호
• /
• pp.509-521
• /
• 2021

The neighbouring gaps at the mortise-tenon joint in traditional timber structure, which leads to the complexity of the joint, are considered to impair the mechanical performance of the joint. In this paper, numerical simulation of loose joint was conducted to examine the deformation states, stress distributions, and bearing capacities, which was verified by full-scale test. On the basis of the experimental and numerical results, a simplified mechanics model with gaps has been proposed to present the bending capacity of the loose joint. Besides, the gap effects and parameter studies on the influences of tenon height, friction coefficient, elastic modulus and axial load were also investigated. As a result, the estimated relationship between moment and rotation angle of loose joint showed the agreement with the numerical results, demonstrating validity of the proposed model; The bending bearing capacity and rotational stiffness of loose joint had a certain drop with the increasing of gaps; and the tenon height may be the most important factor affecting the mechanical behaviors of the joint when it is subjected to repeated load; Research results can provide important references on the condition assessments of the existing mortise-tenon joint.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
• /
• pp.201-206
• /
• 2001

This paper presents truss model that can be used to determine the deformation as well as strength of RC members. This model is constituted to address plastic hinge rotation at tile deformation concentrated regions under severe lateral load. The behavior of each element of truss model is evaluated on the basis of stress field analysis. The deformation is obtained by combining element deformations with joint rotation. Initial strength is calculated at the first failure of any element, and strength deterioration after failure depends on the strength reduction of this element. The proposed model will provide useful tools in seismic design of ductility-required members.

• 대한기계학회논문집
• /
• 제17권8호
• /
• pp.1980-2000
• /
• 1993

The stresses and torque transmission capabilities of adhesively bonded circular, hexagonal and elliptical lap joints were analyzed by the finite element and compared with the experimental results. The adherends of the joints were composed of carbon fiber/epoxy composite shafts and steel shafts. In calculating the torque transmission capabilities, the linear laminate properties of the composite material and the nonlinear shear properties of the adhesive were used. Using this method, the torque transmission capabilities of adhesively bonded lap joints could be obtained within 10% error compared to the experimental results except some single lap joints. The experiments revealed that the hexagonal joint had the best torque transmission capability from the single lap joints and the double lap joint had better torque transmission than the single lap joint.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.1058-1062
• /
• 1996

The assessments of weld defects by fracture mechanics are performed for design of welded Joints. In general, butt, T-type, and L-type welded joint are useful for welding structure. When linear weld defects are in welded joint, stress intensity factors for each joints are calculated by finite element method. Analysis results are shown for the fracture modes and characteristics of joint types. And they are founded for the weaken order of welded joints being T-type, butt, L-type.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.831-836
• /
• 1994

This paper presents rational modeling and analysis method for complex structures with various structural joints. For modeling of structural joint, a general modeling technique is newly proposed by flexibility influence coefficient and inverse of flexibility matrix and static reduction concept which is applied to the retained DOFs(degrees of freedom) of detailed finite element model of struction joints. By this method,joint model with contact surface. which can not be reduced by the general reduction theory such as Guyan reduction theory ,can be reduced effectively. And in this method, the nonlinearity of the contact surface can be linearized within a proper range and the boundary effects of joint region can be excluded. Using the proposed method, screwed joint,glued joint and bolted joint are analyzed. And the effectiveness of the proposed method is verified by experiments.