Structural Modeling and Analysis of Scaffold Systems

Structural equation modeling is used in statistical applications as both confirmatory and exploratory modeling to test models and to suggest the most plausible explanation for a relationship between the independent and the dependent variables. Although structural analysis cannot prove causation, it can suggest the most plausible set of factors that influence the observed variable. We apply structural model analysis to the annual mean Arctic surface air temperature from 1900 to 2012 to find the most effective set of predictors and to isolate the anthropogenic component of the recent Arctic warming by subtracting the effects of natural forcing and variability from the observed temperature. We find that anthropogenic greenhouse gases and aerosols radiative forcing and the Atlantic Multidecadal Oscillation internal mode dominate Arctic temperature variability. Our structural model analysis of observational data suggests that about half of the recent Arctic warming of 0.64 K/decade may have anthropogenic causes.

The purpose of this research is to investigate the interrelationships among the three behavioural constructs of job involvement, job satisfaction and organizational commitment. Accordingly, a structural model is developed to delineate the interactions among these constructs and explore the mediating effect of job satisfaction on the relationship between job involvement and organizational commitment. A questionnaire-based survey was designed to test the aforementioned model based on a dataset of 315 employees working in twelve out of twenty six banks operating in the capital city of Jordan, Amman. The model and posited hypotheses were tested using structural equation modelling analysis. The results indicated that job involvement positively and significantly affects job satisfaction and organizational commitment. Additionally, job satisfaction proved to be positively related to organizational commitment. Furthermore, job satisfaction positively and significantly partially mediated the relationship between job involvement and organizational commitment.

Most of the schools in Italy were built before the introduction of the legislation on structural design in seismic areas. Approximately 25,000 buildings are therefore not adequate to current standards and require in-depth assessments of the seismic safety of structures. This research aims to implement a methodology consisting of the use of information modelling for seismic risk analysis. To assess seismic vulnerability, it is also necessary to analyze the seismic hazard. Two approaches are then tested: the first one is related to structural BIM modeling and structural analysis where information are collected through visual screening during inspections and through the study of existing documentations. The second is a more in-depth approach that includes static and dynamic non-destructive testing and structural FEM analysis. The two models were tested on the main building of a middle school in Milan (Italy).

Structural configuration modeling and finite element analysis of crew exploration vehicle (CEV) concepts are presented. In the structural configuration design approach, parametric solid models of the pressurized shell and tanks are developed. The CEV internal cabin pressure is same as in the International Space Station (ISS) to enable docking with the ISS without an intermediate airlock. Effects of this internal pressure load on the stress distribution, factor of safety, mass and deflections are investigated. Uniform 7 mm thick skin shell, 5 mm thick shell with ribs and frames, and isogrid skin construction options are investigated. From this limited study, the isogrid construction appears to provide most strength/mass ratio. Initial finite element analysis results on the service module tanks are also presented. These rapid finite element analyses, stress and factor of safety distribution results are presented as a part of lessons learned and to build up a structural mass estimation and sizing database for future technology support. This rapid structural analysis process may also facilitate better definition of the vehicles and components for rapid prototyping. However, these structural analysis results are highly conceptual and exploratory in nature and do not reflect current configuration designs being conducted at the program level by NASA and industry.

Earthquakes are known to produce one of the most destructive forces on earth. It has been seen that during past earthquakes many of the building were collapsed. Therefore, realistic method for analysis and design are required. Performance Based Design is the modern approach for earthquake resistant design. It is an attempt to predict the performance of buildings under expected seismic event. It involves the calculation of load and total Seismic weight of building from that the base shear is calculated in different zone. The study is carried out with the help of both manual calculations and ETABS software for a three story building in the campus. Analysis of structure is used to verify the fitness of the structure for use. To perform accurate analysis information such as structural loads, geometry, support condition and material properties should be determined. ETABS is the acronym of extended 3D analysis of building system is software developed by Computers and Structures, Inc. (CSI). ETABS is an engineering software product that can be used to analyze and design multi-story buildings using grid-like geometry, various methods of analysis and solution techniques, considering various load combinations. ETABS can also handle the largest and most complex building models, including a wide range of nonlinear behaviors, making it the tool of choice for structural engineers in the building industry. ETABS can be effectively used in the analysis and design of building structures which might consists of structural members like beams, columns, slabs, shear walls and the like. To perform accurate analysis information such as structural loads, geometry, support condition and material properties should be determined. The results of such an analysis typically include support reactions, stresses and displacements. Advanced structural analysis may examine dynamic response, stability and nonlinear behavior. KEYWORDS: Extended three analysis dimensional system, analysis and comparison, beams, building geometry, material properties

Matrix method for stability and second-order analysis of Timoshenko beam-column structures with semi-rigid connections

일반적으로 건축물의 구조해석과 설계에 있어 작업효율을 확보하기 위하여 상부구조물과 하부구조물을 별도로 모델링하여 해석 및 설계를 진행하는 분리해석 방법을 사용한다. 하지만, 상기 분리해석을 사용할 경우, 상부구조물의 고정지점과 변형된 기초구조물과는 실제 연결된 지점에서 변위차가 발생하여 구조해석의 기본요건인 변형적합성 조건을 만족하지 못하게 되고 상부구조-하부구조의 상호작용을 고려하지 못하기 때문에 실제와는 다른 구조해석 및 설계결과를 초래할 수 있다. 본 연구에서는 초고층 철골구조물을 대상으로 구조물의 부등침하 등에 큰 영향을 미치는 상재(常載)하중에 대한 분리해석과 일체해석의 해석결과 차이를 비교 분석하였다. 분석결과에 따르면 분리해석방법을 사용할 경우, 상부구조물의 구조해석에 있어 기초의 변형을 고려하지 못하기 때문에 부재력을 과소평가할 수 있고 이로인해 비안전측 설계결과를 가지고 올 수 있다. 하부 기초구조물을 분리해석으로 해석하였을 경우, 상부구조물의 강성을 고려하지 못하기 때문에 기초의 부등침하 과대평가, 부재력의 과대/과소 평가를 초래할 수 있어 비경제적이고 불안전한 설계결과를 가져올 수 있다. 특히, 기초의 변형이 상부구조물에 큰 영향을 미칠 수 있는 건축구조물, 지반의 강성이 작아서 기초에 큰 변형이 예상되는 건축물, 지반조건이 불균질하여 부등침하가 예상되는 건축구조물 등에는 분리해석을 지양해야 할 것이다. In the case of structural analysis for building structures, the super-structure and the sub-structure are analyzed by using separate structural models in the field because of time saving, facile result interpretation and easy analysis of dynamic behavior. However this separate structural model violated the compatibility condition of structural analysis and it can not consider the interaction of super- and sub- structures. In the present study, the analysis results of this separate model were compared to those of the unified model of super- and sub- structures which can consider the interaction of super- and sub- structures and reflect the realistic boundary conditions. According to the comparison results, the the analysis model using separate models can underestimate the member force and deflection of structural members in the super-structures and overestimate the deflection and member force of sub-structures. Therefore, in the case of high-rise buildings, irregular shaped buildings, buildings which are expected to be affected by large differential settlement and remodeling buildings, the unified structural model for super- and sub- structures was recommended for structural analysis instead of the separate structural model.

Common features of the extracellular carbohydrate-active virulence factors involved in host-pathogen interactions are their large sizes and modular complexities. This has made them recalcitrant to structural analysis, and therefore our understanding of the significance of modularity in these important proteins is lagging. Clostridium perfringens is a prevalent human pathogen that harbors a wide array of large, extracellular carbohydrate-active enzymes and is an excellent and relevant model system to approach this problem. Here we describe the complete structure of C. perfringens GH84C (NagJ), a 1001-amino acid multimodular homolog of the C. perfringens micro-toxin, which was determined using a combination of small angle x-ray scattering and x-ray crystallography. The resulting structure reveals unprecedented insight into how catalysis, carbohydrate-specific adherence, and the formation of molecular complexes with other enzymes via an ultra-tight protein-protein interaction are spatially coordinated in an enzyme involved in a host-pathogen interaction.

The article provides a structural model for independent work of students in the educational process. This structural model is developed on the basis of functional and structural analysis. It makes it possible to visually represent the learning process as a whole as well as to objectify the process of assessing the independent work of students both for the teacher and the student himself. The developed structural model is general, it is applicable in the process of teaching and assessing independent work both in general education schools, art schools, and in various secondary and higher educational institutions. To concretize the model it is considered in the context of the studied subject supplementing it with specific content. The application of the developed model is shown as an example of music lessons of general and secondary specialized educational institutions with the use of electronic music technologies. Currently there is a contradiction between the large resources of independent work of students and the need to evaluate the process and results of independent work. One of the possible ways to solve this contradiction is to involve the students themselves in the diagnostic process using the methods of functional and structural analysis. The use of the potential of independent work of students contributes to the creation of conditions for self-realization of a person and presupposes the free development of his abilities. This is in line with current trends in education. The article indicates that in the modern education system the role of independent work of students is increasing both in mastering basic knowledge and special knowledge, skills and abilities. In this regard, the problem arises of assessing this work, both by teachers and by the students themselves. It is supposed to involve the students themselves in the process of assessing the independent work on the basis of the methods of functional and structural analysis.

A simple method for combining fire and structural models and its application to fire safety evaluation

Recent research trends have indicated an interest in High-Altitude, Long-Endurance (HALE) aircraft as a low-cost alternative to certain space missions. These missions require a lightweight vehicle operating at low speeds, high lift and minimum drag. These conditions necessitate high-aspect ratio wings. Due to its large span and light weight, the wing structure is very flexible. The wings undergo significant deflections as a result of the fluid loads acting on them, and require the consideration of aeroelastic effects. To reduce the structural deformation and increase the total lift, a sensorcraft model with a joined-wing configuration is employed. The results of the simulation of the complex, three-dimensional flow past the joined wing of a HALE aircraft are used as an input for the structural analysis. In the existing studies to date, only simplified structural models have been examined. In the present work, a semi-monocoque structural model is developed. All stringers, skin panels, ribs and spars are represented by appropriate elements in a finite-element model. Linear and nonlinear static analyses under the aerodynamic load are performed. The stress distribution in the wing is explored. Starting with a structural model with uniform mass distribution, a design optimization is performed. The optimized model has a maximum stress 42% lower and a maximum deflection 26% lower than obtained for the initial model. Linear and nonlinear buckling analyses are performed as well. The nonlinear analysis yields a critical buckling load 18% lower than that predicted by linear analysis. This paper will discuss the details of the structural modeling as well as the results obtained before and after optimizing the model.

Improving Fault Isolability Properties by Structural Analysis of Faulty Behavior Models: Application to the DAMADICS Benchmark Problem

The structural design and analysis of a cryogen-free open superconducting magnet for interventional MRI applications is presented. The magnet assembly consisted of two identical halves connected together by four posts. The magnet separation allows a surgeon access to the patient within the field-of-view of the imaging system. Each half of the assembly consisted of three superconducting coils, a stainless steel bobbin, a copper thermal ring, and three overwrap rings. The suspension components of the magnet consisted of eight radial straps and eight axial rods. A structural analysis was carried out that considered the differential thermal contraction caused by the cooldown to the magnet cryogenic operating temperature, and the electromagnetic forces on the coils when the magnet is energized at the design current value. The results are compared to the equivalent stresses caused by a simulation of a quench that was initiated at the inner diameter of one of the superconducting coils. The post-quench thermal transient analysis predicted a nonuniform 3-D temperature field in the range of 10 to 178 K and asymmetric electromagnetic forces on the superconducting coils. The three dimensional structural model of the assembly was developed in ANSYS.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This research investigates the stability analysis of multi-trigger nanotube-based sandwich structures that carry fluid subjected to external stimulus. Acrylic-based material and magnetorheological elastomers (MRE) are considered multi-trigger cores in which the external stimulus alters the mechanical properties of the core and, subsequently, the sandwich structures. The system is subjected to an external magnetic field while the ambient temperature varies. The results demonstrate that incorporating a multi-trigger viscoelastic core can accelerate the divergence instability of the non-conservative system while delaying its flutter. Additionally, the impact of the external magnetic field, as a control parameter, for the frequency and stability region of the MRE is more significant than that of the Acrylic-based material. Furthermore, employing Acrylic-based material with a higher shear modulus in a constant magnetic field leads to a more stable system. Moreover, the effect of the external magnetic force on stability is affected smoothly by the ambient temperature. Finally, the influence of temperature on stability is nearly the same for both MRE and Acrylic-based material, with a more pronounced effect observed in systems with larger length-to-diameter ratios.

Geometrical nonlinear and stability analysis for slender frame structures of crawler cranes