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Globally, large-scale natural disasters are occurring more frequently due to climatic and environmental changes. In addition, the disaster risk for infrastructures, mainly bridges, has become a vulnerability issue because reinforced concrete bridge structures are being directly exposed to the natural environment. Bridge structures linking cities or prefectures are destroyed in the aftermath of natural disasters and must be rebuilt. As a post-disaster measure, rapid reconstruction of damaged bridges and the reconnection of transportation systems between impacted locations and urban areas are the main problems encountered. This study aims to solve these problems through the application of a novel concept of an emergency bridge based on origami-inspired post-buckling theory, in conjunction with previous studies investigating the optimal deployable structure of scissors-type bridges. This study applied a novel design method for scissor-type bridges that use influence line diagrams and equilibrium equations. The proposed methods can determine the size of each member appropriately while providing the minimum and maximum values of the influence line border when carrying light vehicles by analyzing variations in the live load distribution on the structure. In the case of heavy vehicles passing over a bridge, the fundamental internal axial forces and bending moments were obtained, which provided design parameters for improving the load-carrying capacity of the structure. The proposed emergency bridge has a lower theoretical stress than that of a double-Warren truss.

This paper presents equilibrium mechanics and a finite element model for analysing a scissor structure that contains pivots with zero bending stiffness representing structural instability. The pivot at the centre of each structural unit, which is a feature of scissor structures, can be used to transfer the displacement between the units. It cannot, however, transfer the rotation between these units, and the angular stiffness must be considered independently for each unit. To construct a general model of the scissor structure, a scissor unit was developed using the left and right boundary connections of adjacent units to simulate a periodically symmetric structure. The proposed method allows us to obtain an accurate distribution of the internal forces and deflections without the use of special elements to account for central pivots.

Scissor structures can meet different performance goals by actively changing their geometric configurations. This paper focuses on the inverse design problem of planar scissor structures with end constraints to obtain various forms without changing the span. Two strategies are proposed, one based on adding hinges and the other based on telescopic rods. The corresponding geometrical principles and constraint conditions are formulated. An inverse design framework from two predefined target shapes to design parameters is established, which consist of geometry optimization and mobility assessment. Seven case studies are used to illustrate the design method based on the two strategies. Results show potential for application of morphing planar scissor structure in practice.

In this paper, a novel two-dimensional scissor structure that transforms between concave and convex configurations is presented. The structure is designed by a method of assembling kite or anti-kite loops in the flat configuration. Angulated units are generated from the assembled loops. Finally, a new angulated scissor unit is introduced in order to design the novel scissor structure.

Due to its simple structure and good deployable characteristics, scissor-like structure (SLS) is widely used in many fields, such as mechanical engineering, structure engineering, and aerospace engineering. Because of its inherent structural characteristics, a SLS can possess superior nonlinearities both in equivalent stiffness and damping only with linear component. It also has high loading capacity and excellent equilibrium stability. Thus, it is promising as a vibration isolator. Based on recent findings, a theoretical study is herein executed to build up a universal stiffness model of full types of SLS (including 6 assembly types), considering mass of scissor arm, Coulomb and viscous friction forces in joint parts. Plus more, perturbation method (PM) and average method (AM) are applied to investigate vibration isolation performances of SLS with different assembly types and installation parameters and to compare them with known quasi-zero-stiffness vibration isolators in the literature. Finally, a simulation is done to testify the presented findings and to compare them with former studies. It is shown that: without changing its overall structure and outside dimensions, a SLS vibration isolator can have significantly different nonlinear stiffness for specific nonlinear characteristics only through adjusting assembly type, installation parameters, and initial deformation of its linear component. Since allowable workspace of a vibration isolator is always limited by isolation object and its surrounding structure, this finding indicates a new way to design and modify vibration isolation performance of a system. It will greatly expand application of SLS in vibration isolation.

Scissor-like isolation platform (SIP) with magnetorheological damper (MRD) has been commonly studied and applied successfully in vehicle vibration isolation. This paper concerns passive nonlinear magnetorheological (MR) characteristics of the SIP via geometric nonlinearity induced by MRD’s layout ways. A dynamic parametric model of the SIP with six assembly types is derived based on Lagrange equation. Then, the parameter analysis is performed to estimate MR damping function in SIP. The analytical steady-state response of the isolator is derived using harmonic balance method, and its effectiveness is validated with numerical results. Metrics are defined to access the performance of the isolator, followed by comparison on displacement transmissibility for six types. The effect of MR damping coefficient and input amplitude on the performance of the isolator is investigated. Finally, comparative study with existing isolators is conducted. Results indicate that, passive MR damping is dependent on vibration displacement, which is beneficial to suppressing peak transmissibility with a little effect at non-resonant frequencies. The results also reveal that the isolator by type 1 or 3 has broader isolation band over other types. And the SIP in type 1 has wider isolation band and lower peak transmissibility compared with existing isolators in allowable workspace.

This paper addresses practical sizing optimization of deployable and scissor-like structures from a new point of view. These structures have been recently highly regarded for beauty, lightweight, determine behavior, proper performance against lateral loads and the ability of been compactly packaged. At this time, there is a few studies done considering practical optimization of these structures. Loading considered here includes wind and gravity loads. In foldable scissor-like structures, connections have a complex behavior. For this reason, in this study, the authors used the ABAQUS commercial package as an analyzer in the optimization procedure. This made the obtained optimal solutions highly reliable from the point of view of applicability and construction requirements. Also, to do optimization task, a fast genetic algorithm method, which has been recently introduced by authors, was utilized. Optimization results show that despite less weight for aluminum models than steel models, aluminum deployable structures are not affordable because they need more material than steel structures and cause more environmental damage.

In architectural engineering, deployable scissor structures are generally used for mobile and temporary applications. They are characterised by their dual functionality as either kinematic mechanisms (during deployment) or loadbearing skeletal structures (after deployment). It is crucial to realise that there is a direct and mutual relationship between the geometry, the kinematics and the structural response of the scissor system. Due to a relatively complex design process it can be highly beneficial to evaluate these structures at a pre-design stage in terms of their structural performance. In order to do so, new computational methods are introduced. Karamba is a finite element plug-in for Grasshopper, fully embedded in the 3D modelling software Rhinoceros, which calculates interactively the response of three dimensional beam structures. The advantage of this new tool is the compatibility with the parametric environment of Grasshopper. These software tools are still in development, but already show their potential in terms of geometric modelling and structural optimisation. In this research it is shown in which way these evolving computational methods can contribute to the design of deployable scissor structures. By using the proposed methodology of preliminary evaluation, the scissor structures are geometrically and structurally optimised at an early stage, thereby enhancing the overall design process and facilitating further detailed analysis.

Modeling and simulation refers to using models - physical, mathematical, or otherwise logical representation of a system, entity, phenomenon, or process - as a basis for simulations - methods for implementing a model (either statically or) over time - to develop data as a basis for managerial or technical decision making. The architectural model indicates visualization of internal relationships within the structure or external relationships of the structure within the environment. The geometry of the model and the object it represents are often similar in the sense that one is a rescaling of the other; in such cases the scale is an important characteristic. Physical models allow visualization, from examining the model of information about the thing the model represents. In this study according to Bloom's model, we try to promote learning structural behavior on structural systems course in University of Tehran for bachelor students. The research method been used in this paper, based on the description of the subject property. According to research a Bloom's model, structural physical model is an appropriate way of understanding the structural behavior.

This paper presents a finite element method for the analysis of scissor-link foldable structures. These structures are capable of deforming from compact form to expanded form, and vice versa. Due to their complex mechanism, it is difficult and time-consuming to simulate foldable structures in analysis softwares, while the proposed method of this paper makes it easy to perform the analysis in a simple manner. In addition, this paper uses two different multi-objective meta-heuristic algorithms, NSGAII and MOCBO, to perform optimum design of foldable structures. The purpose is to find designs that result in minimum weight and minimum volume of the structures satisfying all the constraints consisting of maximum stress, elements buckling, and permissible displacement.