Dynamic behavior analysis of rigidflexible coupling planar mechanism considering dry clearances and lubrication clearances

Xiulong Chen,Tao Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.4

In mechanical systems, flexibility of components and clearances of kinematic pairs have significant impacts on dynamic performance. Previously, although many scholars have studied the dynamic behavior of mechanisms considering clearance, few studies have considered rigid-flexible coupling, clearance categories and clearance parameters at the same time. Therefore, the dynamic behavior of rigid-flexible coupling mechanism considering dry clearances and lubrication clearances is of great significance for accurate analysis of dynamic behavior. This paper studied dynamic behaviors of a new planar nine-bar linkage mechanism. The dry and lubrication clearance models are established, and transition force model considering them is introduced. Based on centroid coordinate formulation and absolute nodal coordinate formulation, rigid and flexible beam element models are established. The dynamic model of rigid-flexible coupling mechanism is established based on Lagrangian multiplier formulation. The dynamic behaviors of rigid-flexible coupling mechanism considering dry clearances and lubrication clearances are analyzed. Effects of clearance values and and lubricating viscosities on mechanism are studied.

Dynamic functional connectivity analysis reveals improved association between brain networks and eating behaviors compared to static analysis

Park, Bo-yong,Moon, Taesup,Park, Hyunjin Elsevier 2018 Behavioural brain research Vol.337 No.-

<P><B>Abstract</B></P> <P>Uncontrollable eating behavior is highly associated with dysfunction in neurocognitive systems. We aimed to quantitatively link brain networks and eating behaviors based on dynamic functional connectivity analysis, which reflects temporal dynamics of brain networks. We used 62 resting-state functional magnetic resonance imaging data sets representing 31 healthy weight (HW) and 31 non-HW participants based on body mass index (BMI). Brain networks were defined using a data-driven group-independent component analysis and a dynamic connectivity analysis with a sliding window technique was applied. The network centrality parameters of the dynamic brain networks were extracted from each brain network and they were correlated to eating behavior and BMI scores. The network parameters of the executive control network showed a strong correlation with eating behavior and BMI scores only when a dynamic (<I>p</I> < 0.05), not static (<I>p</I> > 0.05), connectivity analysis was adopted. We demonstrated that dynamic connectivity analysis was more effective at linking brain networks and eating behaviors than static approach. We also confirmed that the executive control network was highly associated with eating behaviors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Links between brain networks and behaviors of eating disorders were explored. </LI> <LI> Executive control network was associated with behaviors of eating disorders and BMI. </LI> <LI> Dynamic, not static, connectivity analysis revealed significant results. </LI> </UL> </P>

반고형 식품류의 정상유동특성 및 동적 점탄성

송기원,장갑식 한국유변학회 1999 Korea-Australia rheology journal Vol.11 No.2

본 연구에서는 Rheometrics Fluids Spectrometer(RFS II)를 사용하여 세 종류의 상용 반고형 식품(마요네즈, 토마토 케찹, 와사비)의 정상유동특성 및 소진폭 전단변형하에서의 동적 점탄성을 광범위한 전단속도와 각주파수 영역에서 측정하였다. 이들 측정결과로부터 정상유동특성의 전단속도 의존성 및 동적 점탄성의 각주파수 의존성을 보고하였다. 그리고 항복응력의 항을 갖는 몇 가지 점소성 유동모델을 사용하여 정상유동특성을 정량적으로 평가하고 이들 모델의 적용성을 비교.검증하였다. 나아가서 수정된 형태의 지수법칙 관계식을 도입하여 정상유동특성(비선형 거동)과 동적 점탄성(선형 거동)간의 상관관계에 대해 검토하였다. 이상의 연구를 통해 얻어진 결과를 요약하면 다음과 같다. (1) 반고형 식품류는 상당한 크기의 항복응력을 갖는 점소성 물질로서 전단속도가 증가할수록 정상류점도가 급격히 감소하는 shear-thinning 거동을 나타낸다. (2) Herschel-Bulkley 모델, Mizrahi-Berk 모델 및 Heinz-Casson 모델은 반고형 식품류의 정상유동거동을 잘 기술할 수 있다. 이들 중에서도 Heinz-Casson 모델이 가장 우수한 적용성을 갖는다 (3) 반고형 식품류는 임계 전단속도를 경계로 shear-thinning 특성이 변화한다. 즉 낮은 전단속도에 비해 높은 전단속도 영역에서 분산입자 응집체의 구조파괴가 더욱 활발하게 진행되어 보다 현저한 shear-thinning 특성을 나타낸다. (4) 저장 탄성률 및 손실탄성률은 양자 모두 각주파수가 증가할수록 점차로 증가하나 각주파수 의존성은 그다지 크지 않다. 또한 광범위한 각주파수 영역에서 탄성적 성질이 점성적 성질에 비해 보다 우세하게 나타난다. (5) 정상류점도, 동적점도 및 복소점도는 모두 power-law 모델의 거동을 잘 만족한다. 또한 정상유동특성과 동적 점탄성간의 상관관계는 수정된 형태의 지수법칙 관계식에 의해 잘 기술될 수 있다. Using a Rheometrics Fluids Spectrometer(RFS II), the steady shear flow and the small-amplitude dynamic viscoelastic properties of three kinds of semi-solid food materials(mayonnaise, tomato ketchup, and wasabi) have been measured over a wide range of shear rates and angular frequencies. The shear rate dependence of steady flow behavior and the angular frequency dependence of dynamic viscoelastic behavior were reported from the experimentally measured data. In addition, some viscoplastic flow models with a yield stress term were employed to make a quantitative evaluation of the steady flow behavior, and the applicability of these models was also examined in detail. Furthermore, the correlations between steady shear flow(nonlinear behavior) and dynamic viscoelastic(linear behavior)properties were discussed using the modified power-law flow equations. Main results obtained from this study can be summarized as follows : (1) Semi-solid food materials are regarded as viscoplastic fluids having a finite magnitude of yield stress, and their flow behavior shows shear-thinning characteristics, exhibiting a decrease in steady flow viscosity with increasing shear rate. (2) The Herschel-Bulkley, Mizrahi-Berk, and Heinz-Casson models are all applicable to describe the steady flow behavior of semi-solid food materials. Among these models, the Heinz-Casson model has the best validity. (3) Semi-solid food materials show a stronger shear-thinning behavior at shear rate region higher than a critical shear rate where a more progressive structure breakdown takes place. (4) Both the storage and loss moduli are increased with increasing angular frequency, but they have a slight dependence on angular frequency. The elastic behavior is dominant to the viscous behavior over a wide range of angular frequencies. (5) All of the steady flow, dynamic, and complex viscosities are well satisfied with the power-law model behavior. The relationships between steady shear flow and dynamic viscoelastic properties can well be described by the modified forms of the power-law flow equations.

선형 동적 시스템 기반의 감정 엔진 모델

안호석(Ho Seok Ahn),최진영(Jin Young Choi) 대한전기학회 2007 대한전기학회 학술대회 논문집 Vol.2007 No.4

This paper introduces an emotional behavior decision model for intelligent service robots. An emotional model should make different behavior decisions according to the purpose of the robots. We propose an emotional behavior decision model which can change the character of emotional model and make different behavior decisions although the situation and environment remain the same. We defined each emotional element such as reactive dynamics, internal dynamics, emotional dynamics, and behavior dynamics by state dynamic equations. The proposed system model is a linear system. If you want to add one external stimulus or behavior, you need to add just one dimensional vector to the matrix of external stimulus or behavior dynamics. The case of removing is same. The change of reactive dynamics, internal dynamics, emotional dynamics, and behavior dynamics also follows the same procedure. We implemented the proposed emotional behavior decision model and verified its performance.

일반 논문 : 동태적인 프랜차이징 시스템 환경에서의 가맹점의 기회주의적 행동과 행동의도에 관한 연구

이재훈 ( Jae Hoon Rhee ),나호섭 ( Ho Seop Na ) 한국중소기업학회 2011 中小企業硏究 Vol.33 No.2

본 연구는 프랜차이즈 시스템의 프랜차이저와 프랜차이지의 관계에서 프랜차이지의 기회주의 행동에 영향을 미치는 선행변수에 대해 살펴보고, 기회주의 행동과 그 선행변수들 간의 관계에서 환경 동태성의 조절효과를 분석하였다. 선행연구 고찰을 통해 기회주의 행동과 그 선행변수들 간의 인과관계를 파악하기 위한 연구가설을 설정하였으며, 이에 기반하여 연구모형을 구축하였다. 가설 검증을 위해 국내 프랜차이즈 시스템에 소속되어 있는 831개의 프랜차이즈를 대상으로 설문조사를 실시하여 자료를 수집하였으며, 다중회귀분석을 실시하였다. 분석 결과, 교환관계의 질은 기회주의 행동에 유의적인 부(-)의 영향을 미치는 것으로 나타났으며, 집중화 정도와 네트워크 크기는 유의적인 정(+)의 영향을 미치는 것으로 나타났다. 또한 기회주의 행동과 그 선행요인들과의 관계에서 환경 동태성의 조절효과를 분석한 결과, 모든 상호작용항이 유의한 부(-)의 영향을 미치는 것으로 나타났다. 결론 부분에서는 연구의 시사점과 한계점 및 향후 연구 방향을 제시한다. Economically operating, a franchise system is being widely recognized as an organizational system that can flexibly respond to a fast-changing business environment. The system is of particular use, in that it could help small businesses with resource constraints to be competitive by providing an opportunity of utilizing outsourcing strategies rather than an integrated structure of firms. In this sense it appears that such a decentralized structure system is greatly attractive to franchisees. Research on the franchise system is based on three theoretical foundations: resource dependence theory, agency theory and transaction cost theory. From the resource dependence perspective, for instance, it is plausible to assume that a franchiser who establishes a new franchise system easily and usefully can attempt to overcome its own resource deficiency by securing a sufficient number of franchisees. This clearly indicates that the franchise system can be beneficial to both of parties. Literature highlights that the key is to mitigate opportunistic behavior by franchisees for a successful operation of a franchise system. The transaction cost theory provides a sound theoretical explanation of why the success of the franchise system in business relies, to a great extent, on effectively managing the opportunism. This study explores the nature and characteristics of opportunistic behavior acted by a franchisee and its antecedents and attempts to analyze their causal relationships in a franchise system. Regarding moderators in the linkages between opportunistic behavior and its antecedents, a vast majority of research focuses on how the concept of trust can be well built up to reduce the opportunistic behavior. From this point of view, a particular emphasis is placed on the moderating effects of environmental dynamism between the linkages. Drawing on relevant literature, six major research hypotheses are developed to empirically clarify the effect of the antecedents on the opportunistic behavior and a conceptual model that illustrates the hypothesized paths is constructed. H1: In a franchise system, quality of relations between a franchiser and franchisee will have a negative effect on the propensity to act opportunistically or on opportunistic behavior. H2: In a franchise system, firm-specific investment in terms of franchisees will have a negative effect on the propensity to act opportunistically or on opportunistic behavior. H3: In a franchise system, the higher the extent of centrality, the greater the possibility of acting with opportunism. H4: In a franchise system, network size measured as the number of franchisees will have a positive effect on the propensity to act opportunistically or on opportunistic behavior. H5: In a franchise system, dependency will have a negative effect on the propensity to act opportunistically or on opportunistic behavior. H6: In a franchise system, environmental dynamism will moderate the relationship between all the antecedents and opportunistic behavior. To test the hypotheses, data is gathered from a total of 831 franchisees that are identified as operating in domestic franchise systems using questionnaires and multiple regression analyses are run. Results reveal that quality of relations between a franchiser and franchisee is found to significantly and positively affects opportunistic behavior. This finding indicates that franchisees could seek to avoid acting with opportunism when the franchisees perceive and recognize positively support provided by a franchiser and the franchisees voluntarily cooperate with their franchiser toward a mutual gain. It is also found that the higher the extent of centrality, the greater the possibility of acting with opportunism. In general, centrality tends to go hand in hand with the relatively lower level of opportunism in an organization. In a franchise system, however, it is clear that a franchise`s headquarter has a limited level of control over franchisees as it has a form of the horizontal structure due to geographical disperse. Because of this line of reasoning, an attempt to get the level of control high could make franchisees recognize that a franchiser has a lower degree of trust for them, thereby leading to the high extent of opportunism. The results also indicate that network size measured as the number of franchisees has a positive effect on the propensity to act opportunistically in a franchise system. On the contrary, two other independent variables are found to insignificantly affect the consequence. More importantly, the results of moderated regression analysis show that environmental dynamism is a significant moderating variable in the relationship between all the antecedents of opportunistic behavior suggested in the present study and the consequence. It is also found that the moderator is even significant in the linkage between the dependent variable and two independent variables-firm-specific investment and dependency - which are found to be insignificant in a linear regression analysis. This finding proves that franchisees that operate in a very dynamic business environment have a tendency to be strongly tied to their franchiser. From these findings, several implications are presented. Since this research would be the first to place emphasis on environmental dynamism as a moderator that is expected to reduce an opportunistic propensity in a franchise system, it broadens the theoretical scope for research into a franchise system. This research also pays attention to the importance of network size in elucidating one of the reasons for opportunistic behavior of franchisees. Results indicate that the size of the network must be taken into careful account so as for a franchisee to avoid acting opportunistically to a significant extent. It provides a managerial implication that the franchise business should be run with the appropriate number of franchisees that a franchiser can take control over effectively. Additionally, the result shows that interaction between firm-specific investment and environmental dynamism plays a significant role in decreasing franchisees` opportunistic behavior. This denotes that, under an intensified dynamic and competitive environment, a franchisee is likely to invest firm-specific assets toward its franchise` policy. Although it has these contributions and many practical implications, the present study also has some limitations. The analysis depends totally on one-way based data obtained by franchisees, which has the limitation of not reflecting the intention of the franchiser, thereby having room of occurring bias. This suggests that it would be meaningful if further research is conducted with dyadic data. Including the quality of communications and reputation of a franchise, more antecedents of opportunistic behavior need to be taken into consideration to have more robust results. In addition, it should be fruitful to link opportunistic behavior to performance. To perform a more robust test, it would be necessary to take account of other extraneous factors such as the prior business experience of a franchise`s founder and ownership types which also could be influential on opportunism of franchisees in the relationship.

Rheology of concentrated xanthan gum solutions: Oscillatory shear flow behavior

Song Ki-Won,Kuk Hoa-Youn,Chang Gap-Shik The Korean Society of Rheology 2006 Korea-Australia rheology journal Vol.18 No.2

Using a strain-controlled rheometer, the dynamic viscoelastic properties of aqueous xanthan gum solutions with different concentrations were measured over a wide range of strain amplitudes and then the linear viscoelastic behavior in small amplitude oscillatory shear flow fields was investigated over a broad range of angular frequencies. In this article, both the strain amplitude and concentration dependencies of dynamic viscoelastic behavior were reported at full length from the experimental data obtained from strain-sweep tests. In addition, the linear viscoelastic behavior was explained in detail and the effects of angular frequency and concentration on this behavior were discussed using the well-known power-law type equations. Finally, a fractional derivative model originally developed by Ma and Barbosa-Canovas (1996) was employed to make a quantitative description of a linear viscoelastic behavior and then the applicability of this model was examined with a brief comment on its limitations. Main findings obtained from this study can be summarized as follows: (1) At strain amplitude range larger than 10%, the storage modulus shows a nonlinear strain-thinning behavior, indicating a decrease in storage modulus as an increase in strain amplitude. (2) At strain amplitude range larger than 80%, the loss modulus exhibits an exceptional nonlinear strain-overshoot behavior, indicating that the loss modulus is first increased up to a certain strain amplitude(${\gamma}_0{\approx}150%$) beyond which followed by a decrease in loss modulus with an increase in strain amplitude. (3) At sufficiently large strain amplitude range (${\gamma}_0>200%$), a viscous behavior becomes superior to an elastic behavior. (4) An ability to flow without fracture at large strain amplitudes is one of the most important differences between typical strong gel systems and concentrated xanthan gum solutions. (5) The linear viscoelastic behavior of concentrated xanthan gum solutions is dominated by an elastic nature rather than a viscous nature and a gel-like structure is present in these systems. (6) As the polymer concentration is increased, xanthan gum solutions become more elastic and can be characterized by a slower relaxation mechanism. (7) Concentrated xanthan gum solutions do not form a chemically cross-linked stable (strong) gel but exhibit a weak gel-like behavior. (8) A fractional derivative model may be an attractive means for predicting a linear viscoelastic behavior of concentrated xanthan gum solutions but classified as a semi-empirical relationship because there exists no real physical meaning for the model parameters.

안티푸라민-에스^® 로션의 레올로지 특성 연구

국화윤,송기원,Kuk, Hoa-Youn,Song, Ki-Won 한국약제학회 2009 Journal of Pharmaceutical Investigation Vol.39 No.3

Using a strain-controlled rheometer [Advanced Rheometric Expansion System (ARES)], the steady shear flow properties and the dynamic viscoelastic properties of $Antiphlamine-S^{(R)}$ lotion have been measured at $20^{\circ}C$ (storage temperature) and $37^{\circ}C$ (body temperature). In this article, the temperature dependence of the linear viscoelastic behavior was firstly reported from the experimental data obtained from a temperature-sweep test. The steady shear flow behavior was secondly reported and then the effect of shear rate on this behavior was discussed in detail. In addition, several inelastic-viscoplastic flow models including a yield stress parameter were employed to make a quantitative evaluation of the steady shear flow behavior, and then the applicability of these models was examined by calculating the various material parameters. The angular frequency dependence of the linear viscoelastic behavior was nextly explained and quantitatively predicted using a fractional derivative model. Finally, the strain amplitude dependence of the dynamic viscoelastic behavior was discussed in full to elucidate a nonlinear rheological behavior in large amplitude oscillatory shear flow fields. Main findings obtained from this study can be summarized as follows : (1) The linear viscoelastic behavior is almostly independent of temperature over a temperature range of $15{\sim}40^{circ}C$. (2) The steady shear viscosity is sharply decreased as an increase in shear rate, demonstrating a pronounced Non-Newtonian shear-thinning flow behavior. (3) The shear stress tends to approach a limiting constant value as a decrease in shear rate, exhibiting an existence of a yield stress. (4) The Herschel-Bulkley, Mizrahi-Berk and Heinz-Casson models are all applicable and have an equivalent validity to quantitatively describe the steady shear flow behavior of $Antiphlamine-S^{(R)}$ lotion whereas both the Bingham and Casson models do not give a good applicability. (5) In small amplitude oscillatory shear flow fields, the storage modulus is always greater than the loss modulus over an entire range of angular frequencies tested and both moduli show a slight dependence on angular frequency. This means that the linear viscoelastic behavior of $Antiphlamine-S^{(R)}$ lotion is dominated by an elastic nature rather than a viscous feature and that a gel-like structure is present in this system. (6) In large amplitude oscillatory shear flow fields, the storage modulus shows a nonlinear strain-thinning behavior at strain amplitude range larger than 10 % while the loss modulus exhibits a weak strain-overshoot behavior up to a strain amplitude of 50 % beyond which followed by a decrease in loss modulus with an increase in strain amplitude. (7) At sufficiently large strain amplitude range (${\gamma}_0$>100 %), the loss modulus is found to be greater than the storage modulus, indicating that a viscous property becomes superior to an elastic character in large shear deformations.

Dynamic Path Planning Based on Fuzzy and Behavior Control Idea

Lei Yanmin,Xing Xiaoxue,Feng Zhibin,Guan Xiuli,Du Limin 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12

In order to solve dynamic path planning problem of multi-robot systems in unknown dynamic environment, a kind of method based on fuzzy and behavior control idea was proposed in this paper. This method designs two fuzzy controllers, which are danger degree fuzzy controller and velocity fuzzy controller. They took fully into account the position and the velocity of the obstacle and the azimuth of the target. Fuzzy rules were designed based on behavior control idea and which reflected move-to-goal behavior, avoid-obstacle behavior and follow-obstacle behavior. The experimental results show that the proposed method is feasible and valid and is suitable for the dynamic and complicated environment in particularly.

진동대 시험에 의한 편평한 암석 절리면의 동적 마찰거동 특성

박병기(Byung-Ki Park),전석원(Seokwon Jeon) 한국암반공학회 2006 터널과지하공간 Vol.16 No.1

암반구조물의 규모가 점차 대형화됨에 따라 암반이 자유면에 노출되는 확률이 높아지고 있으며, 최근 들어 지진이나 발파, 고속철도의 운행에 의한 진동 등으로 야기되는 동적 하중의 발생빈도가 증가하는 추세이므로 동적 하중조건 하에서 암반 불연속면의 거동 특성 파악을 위한 연구의 필요성이 증대되고 있다. 본 연구에서는 자유면에 노출된 블록의 동적 거동을 모사할 수 있도록 경사면 진동대 시험장비를 제작하였고, 다양한 동적 하중 조건하에서 편평한 화강암 절리면의 마찰 거동 특성을 분석하였다. 경시시험을 통해서 구한 한계 경사각과 진동하중 하에서의 임계가속도로부터 역산한 정적 마찰각을 비교한 결과 동하중 하에서 정적마찰각이 4.5~8.2˚ 정도 낮게 산정되는 경향을 보였다. 이론적인 암석 블록의 마찰 거동을 표현하는 블록 거동 프로그램을 작성하고, 진동하중에 의해 미끄러지는 암석 블록의 기속도 및 변위 계측결괴를 개발된 프로그램에 의한 결과와 비교하여 임석 절리면의 동적 마찰각을 신정하였는데 동적 마찰각 역시 한계 경사각에 비해 2.0~7.5˚ 정도 감소하는 결과를 얻었다. 동하중 하에서 측정된 정적 마찰각과 동적 마찰각은 가해진 가속도의 크기나 진폭 등의 하중 특성과 기하조건에 따라 달라지는 경향을 보였다. 개별요소 프로그램을 이용하여 진동대 시험을 모사하였는데, 계측결과 및 개발된 프로그램에 의한 결과와 비교적 잘 일치하였다. 진동대 시험에 의한 동적, 정적 마찰각은 직접전단시험에 의한 기본 마찰각보다 현저히 작게 산정되었다. In recent years, not only the occurrences but the magnitude of earthquakes in Korea are on an increasing trend and other sources of dynamic events including large-scale construction, operation of high-speed railway and explosives blasting have been increasing. Besides, the probability of exposure for rock joints to free faces gets higher as the scale of rock mass structures becomes larger. For that reason, the frictional behavior of rock joints under dynamic conditions needs to be investigated. In this study, a shaking table test system was set up and a series of dynamic test was carried out to examine the dynamic frictional behavior of rock joints. In addition, a computer program was developed, which calculated the acceleration and deformation of the sliding block theoretically based on Newmark sliding block procedure. The static friction angle was back-calculated by measuring yield acceleration at the onset of slide. The dynamic friction angle was estimated by closely approximating the experimental results to the program-simulated responses. As a result of dynamic testing, the static friction angle at the onset of slide as well as the dynamic friction angle during sliding were estimated to be significantly lower than tilt angle. The difference between the tilt angle and the static friction angle was 4.5 ~ 8.2° and the difference between the tilt angle and the dynamic friction angle was 2.0~7.5°. The decreasing trend was influenced by the magnitude of the base acceleration and inclination angle. A DEM program was used to simulate the shaking table test and the result well simulated the experimental behavior. Friction angles obtained by shaking table test were significantly lower than basic friction angle by direct shear test.

절리의 방향성을 고려한 암반의 동적거동 수치해석

하태욱(Tae-Wook Ha),양형식(Hyung-Sik Yang) 한국암반공학회 2006 터널과지하공간 Vol.16 No.5

암반구조물의 동적 거동은 구조물이 위치하는 동적 물성과 입력지진파의 특성에 따라 크게 다르며, 절리군이 발달한 암반은 블록의 역학적인 특성과 함께 불연속면의 구조적, 역학적 특성에 따라 다르다. 본 연구에서는 불연속체 해석 기법인 UDEC을 이용하여 지하구조물 주변에 발달한 불연속체의 구조적인 특징에 따라 변화하는 암반의 동적 거동을 평가하고, 이를 연속체 해석 기법인 FLAC<SUP>2D</SUP>의 결과와 비교를 통해 절리 암반의 지진에 대한 동적 거동의 타당성을 비교 검토하였다. 그 결과, 불연속체가 고려된 해석 결과는 절리의 거동에 의한 영향으로 구조적인 형상에 따른 변화가 나타났으며, 연속체 해석 결과는 불연속체 해석 결과에 비해 과다 평가되는 것으로 나타났다. Dynamic behavior of rock structures depends largely on the dynamic characteristics of ground and input earthquake wave. For blocky rocks with intense discontinuities, the mechanical characteristics of blocks and structural and mechanical characteristics of discontinuities affect overall behavior. In this study, UDEC was adopted to evaluate the dynamic behavior of rocks with various structural characteristics. Obtained results were compared to those of FLAC<SUP>2D</SUP>, a continuum analysis, and the validity of the method was examined for dynamic analysis of discontinuous rocks for earthquake. Analysis considering the discontinuity showed significant changes in structural shape by the influence of joint behavior, and the behavior by continuum analysis was overestimated.