• International Journal of Concrete Structures and Materials
• /
• 제11권2호
• /
• pp.403-413
• /
• 2017

Residual axial capacity from numerical analysis was widely used as a critical indicator for damage assessment of reinforced concrete (RC) columns subjected to blast loads. However, the convergence of the numerical result was generally based on the displacement response, which might not necessarily generate the correct post-blast results in case that the strain softening behavior of concrete was considered. In this paper, two widely used concrete models are adopted for post-blast analysis of a RC column under blast loading, while the calculated results show a pathological mesh size dependence even though the displacement response is converged. As a consequence, a nonlocal integral formulation is implemented in a concrete damage model to ensure mesh size independent objectivity of the local and global responses. Two numerical examples, one to a RC column with strain softening response and the other one to a RC column with post-blast response, are conducted by the nonlocal damage model, and the results indicate that both the two cases obtain objective response in the post-peak stage.

• 한국의류학회지
• /
• 제23권1호
• /
• pp.90-110
• /
• 1999

Understanding consumer complaining behaviors plays a key role in post-purchase satisfaction customer retention and long-term customer relationships. This research was conducted to empirically investigate 1) the taxonomy of complaining behavior 2) causes and types of clothing complaining behavior according to sex. The subjects compoed of 250 male and 358 female consuemrs. Data were colleted through questionnaires employing the critical incident methodology. The findings indicated that clothing complaining behavior was fitted well into Singh(1998)'s three-factor model(i. e. voice/private / third-party complaining behaviors) these factors explained 53% of the total variances 75.1% of male and 65.2% of female group complained of poor instruental performance. The types of complaining behaviors were no action negative word-of-mouth to friends and associates n order. Most dissatisfied consumers didn't assert positive consumer's right. Marketer should increase the accessibility of their complaint receiving mechanisms to passive customers.

• 한국학교보건학회지
• /
• 제15권2호
• /
• pp.167-182
• /
• 2002

The purpose of this study was to examine the factors related to adolescence' post-sexual assault attitudes and behaviors. 906 students from 5girls high schools completed self-reported questionnaires. Independent variables are sexual attitudes, rape myth acceptance, perceived importance of sexuality education, parent sexuality education, parent closeness, parent superintendence, family functioning and socioeconomic variables. The data were analyzed by Factor Analysis, Correlation Analysis, Stepwise Multiple Regression Analysis using SPSS program. The significant influencing factors were home sexuality education, perceived necessity & importance of sexuality education, parent closeness, parent superintendence, family functioning, grade, vocational school, rape myth(rapists are mentally ill, dating partner would not be rapist. rapists are stranger), sexual attitudes(sexual permissiveness, gender equality, family planning, STDs & prostitution, marriage and divorce and abortion), and dating experience. Examination of barriers to post-sexual assault coping behaviors and attitudes is critical component of victim recovery and rape prevention. This study would gives basic information to the effective prevention and coping program development related to sexual assault.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.381-386
• /
• 2007

The present study is concerned with the application of Constant arc-length method that proposed by Crisfield in the investigation of the geometrically nonlinear behaviour of spatial structures composed by truss or beam element. The arc-length method can trace the full nonlinear equilibrium path of Spatial structure far beyond the critical point such as limit or bifurcation point. So, we have developed the constant arc-length method of Crisfield to analysis spatial structure. The finite element formulation is used to develop the 3d truss/beam element including the geometrical nonlinear effect. In an effort to evaluate the merits of the methods, extensive numerical studies were carried out on a number of selected structural systems. The advantages of Constant arc length method in tracing the post-buckling behavior of spatial structures, are demonstrated.

• Structural Engineering and Mechanics
• /
• 제35권2호
• /
• pp.191-203
• /
• 2010

To investigate the critical buckling load and post-buckling behavior of an axially loaded pile entirely embedded in soil, the non-linear large deflection differential equation for a pinned pile, based on the Winkler-model and the discretionary distribution function of the foundation coefficient along pile shaft, was established by energy method. Assuming that the deflection function was a power series of some perturbation parameter according to the boundary condition and load in the pile, the non-linear large deflection differential equation was transformed to a series of linear differential equations by using perturbation approach. By taking the perturbation parameter at middle deflection, the higher-order asymptotic solution of load-deflection was then found. Effect of ratios of soil depth to pile length, and ratios of pile stiffness to soil stiffness on the critical buckling load and performance of piles (entirely embedded and partially embedded) after flexural buckling were analyzed. Results show that the buckling load capacity increases as the ratios of pile stiffness to soil stiffness increasing. The pile performance will be more stable when ratios of soil depth to pile length, and soil stiffness to pile stiffness decrease.

• Structural Engineering and Mechanics
• /
• 제44권1호
• /
• pp.109-125
• /
• 2012

Post-buckling behavior of Timoshenko beams subjected to uniform temperature rising with temperature dependent physical properties are studied in this paper by using the total Lagrangian Timoshenko beam element approximation. The beam is clamped at both ends. In the case of beams with immovable ends, temperature rise causes compressible forces end therefore buckling and post-buckling phenomena occurs. It is known that post-buckling problems are geometrically nonlinear problems. Also, the material properties (Young's modulus, coefficient of thermal expansion, yield stress) are temperature dependent: That is the coefficients of the governing equations are not constant in this study. This situation suggests the physical nonlinearity of the problem. Hence, the considered problem is both geometrically and physically nonlinear. The considered highly non-linear problem is solved considering full geometric non-linearity by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The beams considered in numerical examples are made of Austenitic Stainless Steel (316). The convergence studies are made. In this study, the difference between temperature dependent and independent physical properties are investigated in detail in post-buckling case. The relationships between deflections, thermal post-buckling configuration, critical buckling temperature, maximum stresses of the beams and temperature rising are illustrated in detail in post-buckling case.

• 대한가정학회지
• /
• 제33권4호
• /
• pp.199-212
• /
• 1995

The purpose of this study were (1) to find out if socio-demographic, resource, psychological, and socio-environmental variables have significant effect6s on environmentally concious consumer behavior and (2) to examine the independent influences of variables related to the environmentally concious behavior. the subjects were 384 housewives living in Kwangju. the data were collected by questionnare methods and analyzed through SPSS PC+ program. The findings were as follows : Environmentally concious behavior differed significantly according to family income, employment, attending a consumer education experience, knowledge about environmental conservation method, post-industrial consumer value orientation, awareness of the seriousness of environmental problems, feeling of efficacy about helping to solve environmental problems, perception of time limit, influence of reference group and the degree of interesting in environmental information. The most critical variable was influence of reference group, that is, environmentally concious behavior by friends and neighbors.

• Computers and Concrete
• /
• 제26권6호
• /
• pp.467-482
• /
• 2020

This research focused on analyzing the post-fire behavior of high-performance concrete-filled steel tube (CFST) columns, with the concrete containing tire rubber and steel fibers, under axial compressive loading. The finite element (FE) modeling of such heated columns containing recycled aggregate is a branch of this field which has not received the proper attention of researchers. Better understanding the post-fire behavior of these columns by measuring their residual strength and deformation is critical for achieving the minimum repair level required for structures damaged in the fire. Therefore, to develop this model, 19 groups of confined and unconfined specimens with the variables including the volume ratio of steel fibers, tire rubber content, diameter-to-thickness (D/t) ratio of the steel tube, and exposure temperature were considered. The ABAQUS software was employed to model the tested specimens so that the accurate behavior of the FE-modeled specimens could be examined under test conditions. To achieve desirable results for the modeling of the specimens, in addition to the novel procedure described in this research, the modified versions of models presented by previous researchers were also utilized. After the completion of modeling, the load-axial strain and load-lateral strain relationships, ultimate strength, and failure mode of the modeled CFST specimens were evaluated against the test data, through which the satisfactory accuracy of this modeling procedure was established. Afterward, using a parametric study, the effect of factors such as the concrete core strength at different temperatures and the D/t ratio on the behavior of the CFST columns was explored. Finally, the compressive strength values obtained from the FE model were compared with the corresponding values predicted by various codes, the results of which indicated that most codes were conservative in terms of these predictions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제34권4호
• /
• pp.456-459
• /
• 2008

Post-operative recurrence of cystic lesion is a great concern for clinician, patients, and their family, especially in case of odontogenic keratocyst, which has aggressive behavior and high recurrence rate. The purpose of this study was to evaluation clinical characters of OKC, focusing of the recurrence rate and proposed critical follow-up period. 58 cases (aged 9 to 66, 33 males and 25 females) of OKC were reviewed for sex of patients, location, size, operative procedure type, radiographic findings, histopathologic findings, post-operative recurrence time, from 2000 to 2005 at Yonsei Medical Center, were selected. The computerized statistical analysis was carried out with SAS system. 18 of 58 cases (31.03%) were recurred and this study revealed no statistically significant difference in recurrence rate for sex, location, size, radiographic findings, histopatologic findings, operative procedure type, recurrence timing. 3 out of 18 cases (16.7%) showed one or more recurrence. This was statistically significant difference (P=.0264). In this study, 15 of 18 cases (83.3%) were observed recurrence during 4 years after removal of the OKCs, we suggest critical follow-up period during 4 years after operation.

• 한국구조물진단유지관리공학회 논문집
• /
• 제24권4호
• /
• pp.91-99
• /
• 2020

콘크리트용 앵커볼트는 콘크리트 구조물에 대한 비구조요소의 정착에 주로 사용되고 있으며, 시공성의 이점에 따라 후설치앵커가 주로 사용되고 있다. 앵커의 저항 성능과 관련하여 콘크리트 쪼개짐 영향을 최소화하기 위한 위험 연단거리가 제시되고 있지만 실제 앵커의 경우 이상적인 연단거리를 확보하기 어렵다. 즉, 인장 하중에 따라 발생 가능한 콘크리트 쪼개짐 등 복합적인 요소가 포함된 앵커의 저항 성능과 인장 거동 특성을 파악하기 위함이 본 연구의 목적이다. 표준시험방법을 바탕으로 인장실험을 진행하고 도출된 하중-변위 결과 및 파괴 형상을 분석하였다. 위험 연단거리가 확보되지 않은 앵커의 경우 인장력에 의해 콘크리트 쪼갬 파괴가 동반된 파괴 모드가 도출되고 저항 특성은 강성 구간으로 분류된다. 또한, 실험체 구성 요소를 바탕으로 비선형 유한요소모델을 구성하였으며, 앵커 거동을 모사하기 위해 구속 조건 및 연결요소 조건에 따른 경계조건별 변수 해석을 수행하였다. 이에 따라 도출된 해석 결과는 콘크리트 내부 파괴 영향성 및 실제 앵커의 거동을 바탕으로 검증하여 범용구조해석 프로그램 내 경계조건을 통한 저항 메커니즘 적용이 가능한 것으로 판단된다.