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Historical wooden trusses carry a lot of information about used tools, technologies or construction processes. Unfortunately they are generally threatened by many dangers, which could cause irreparable damage and loss of the carried information. Protection of historical roof trusses is an important part of efforts to protect our cultural heritage. Wood destroying insects and fungi are the most serious threats to historical roof trusses in our climatic conditions. Their spreading depends on several specific (interior) conditions. These include critical moisture content in the wood, relative humidity, temperature, etc. In addition to these commonly monitored parameters (and their critical levels) we also must not forget the influence of local geography, biotope or orientation to the cardinal. This paper describes temporal fluctuations of some of the mentioned physical parameters in a historical roof truss (in Brno, Czech Republic) with regard to external climatic conditions and orientation to the cardinal.

Structural design of high rise buildings is governed by lateral loads due to wind or earthquake. As the height of building increases, the lateral load resisting system becomes more important than the structural system that resists the gravitational loads. Recently, diagrid structural system are widely used for tall buildings due to its structural efficiency and flexibility in architectural planning. Diagrid structural system is made around the perimeter of building in the form of a triangulated truss system by intersecting the diagonal and horizontal members. Diagonal members in diagrid structural systems can carry gravity loads as well as lateral loads. Lateral loads are resisted by axial action of the diagonals compared to bending of vertical columns in framed tube structure. The structural efficiency of diagrid system also helps in avoiding interior and corner columns, thereby allowing significant flexibility with the floor plan. In this paper, effect of lateral loads on steel diagrid buildings are studied. Square and rectangular buildings of same plan area with diagrid structural system is considered for the study. Diagrid modules extending upto 2,4,6,8 and 12 storeys are evaluated. Static analysis for the gravity loads, wind and earthquake and response spectrum analysis are carried out for these different combinations of plan shape and diagrid modules and performance of all these diagrid models i.e., storey displacement, storey drift and modal time period are evaluated and compared in this study.

This paper investigates the nonlinear dynamics and stability of the shallow von Mises truss, which is a prototype for buckling analysis of several planar and spatial truss systems and shallow lattice shell structures, including the geodesic dome, and which has a theoretical and practical interest in many engineering fields. These structural systems are liable to limit point instability and may fail at load levels well below the theoretical limit point load due to complex nonlinear phenomena that reduce the safety and the dynamic integrity of the structure; this often occurs as a consequence of the erosion of the basins of attraction of the safe pre-buckling solutions. So, it is vital to increase the safety of the structure in a dynamic environment. In this paper a method for controlling the global nonlinear dynamics of mechanical systems is applied to the shallow von Mises truss. The method consists of the (optimal) elimination of homoclinic intersection by properly adding superharmonic terms to a given harmonic excitation. By means of the solution of an appropriate optimization problem, it is possible to select the amplitudes and the phases of the added superharmonics in such a way that the manifolds distance is as large as possible. This methodology is here applied to increase the integrity of the basins of attraction of the system and consequently its practical safety.

This paper reports the results of an experimental campaign conducted on a set of eight composite beams made of prefabricated steel trusses encased in structural concrete. The test setup is organized in such a way to apply an evenly distributed load on the beam, so to simulate the actual loading condition in real buildings. This is also to avoid the formation of peculiar and unusual shear resisting mechanisms occurring in three or four-point bending tests. The experimental results are presented in terms of force-displacement graphs and also in terms of stress-strain diagrams in the steel members. The outcome of this study highlights that Composite Truss Beams (CTBs) have an effective performance in the shear resisting mechanism, showing a capacity higher than that estimated through the current capacity equations given by Codes.

In the paper the main results of numerical study presented in Gambarelli et al. [1] on concrete elements confined by carbon fiber reinforced polymer (CFRP), are overviewed. Furthermore, preliminary results of numerical simulations performed at mesoscale are presented.The numerical study is based on a extensively experimental campaign conducted by Wang and Wu [2] on small CFRP-confined concrete columns loaded in uni-axial compression. The specimens are characterized by constant size but different cross-section corner radius (from square to circular cross section). The experimental results clearly demonstrate that CFRP confinement is much less effective in square then in circular cross-section.Several numerical models have been performed at macro-scale and meso-scale to confirm the predictability of the used numerical approach, based on the microplane constitutive law for concrete [3]. In the finite element model carbon fibers (truss FE) are embedded into matrix (solid 3D FE). The same as for concrete, the constitutive law for matrix is also based on the microplane model.It is demonstrated that the numerical model is able to predict behavior of confined concrete columns from the experimental investigations. Therefore, the results of the study confirm the predictability of the used numerical approach.

Punching shear is a common failure mode occurring at the slab-column connection region of a reinforced concrete (RC) flat plate. Progressive collapse of RC flat plates poses a significant scientific question on the post punching behaviour of such a structural system. The challenge lies in the complex interactions amongst various internal actions including large unbalanced moments and shear forces. Existing numerical models are unable to differentiate the influence of each individual action within the connection region after punching occurs. Therefore, a new numerical model is required to model these actions individually as well as to evaluate their interrelationships. This paper thus aims to propose a numerical method to investigate the structural response of RC slab-column connections by using a micro model, based on a representative post punching failure experiment. In the micro model, concrete is simulated using solid elements whilst the reinforcement is modelled with truss elements. In this micro model, the constitutive laws and failure criteria of materials play a crucial role in describing the model’s structural behaviour. A typical structural response is discussed and a calibration method is established. Ultimately this study is expected to facilitate the development of an effective, yet simplified numerical model for future progressive collapse simulation of slab-column connections.

This paper presents an innovative technology in the field of truss structures, which is based on an innovative concept of mixing two different types of materials and joining them with a newly conceived connection, able to carry high loads with a small size. After an initial feasibility study aimed at pursuing the realization of sustainable and green structures, the project of the hybrid space truss was finally developed. Here, hybridization is the keyword, that is, making use of two different building materials, steel and wood, to achieve lighter roofs through a specialization of their functions and an optimization of their mechanical properties. Another key point is modularity, which is an important aspect that allows easy and fast assembly of structures and, most of all, standardization of parts. The trusses have been designed in detail, with special attention to the connections, and have been built and tested at the Laboratories of the Hunan University at Changsha (China). In a typical process of “designing by experimenting”, the prototypes have been produced and the assembly process has been tested in order to confirm the feasibility of the whole process, from production to construction to ultimate performance conditions.

Adding braces to moment frames is considered to be quite an efficient technique for increasing the global stiffness and strength of the structure. It has not only been used in steel moment frames, but also in reinforced concrete (RC) moment frames in recent years. It certainly can increase the energy absorption capacity of structures and also decrease the demand imposed by seismic ground motions. Steel braces are anchored firmly to boundary beams and columns. They are modeled as truss elements and increase earthquake resistance of the building. Buckling restrained braced frames (BRBFs) in which members yield under both tension and compression without significant buckling have been used in recent years in order to ensure the desired seismic performance of special concentrically braced frames. BRBFs are similar to the special concentrically braced frames in that seismic accelerations are resisted by a building-frame members and diagonal braces whereas the design procedure is different. BRBs should be designed to permit ductile yielding both in compression and tension. In this paper, flat-slab RC building with two different configurations of buckling restraint braces (BRBs) is studied. The buildings have 4-storey with 5 bays in both X-and Y-directions and have been designed according to Turkish Specification of Reinforced Concrete Design (TS 500). In order to explore overall behavior up to failure and lateral load resisting capacities for these buildings, nonlinear static analyses have then been performed using SAP 2000-V14.1. Pushover analysis under constant gravity loads and monotonically increasing lateral forces during an earthquake until a target displacement is reached is generally carried out as an effective tool for performance based design. The major outcome of a pushover analysis is the capacity curve which shows the base shear vs. the roof displacement relationship and represents the overall performance of the building. The results of the analyses are presented in terms of capacity curve and energy dissipation.

This paper presents an experimental work about the design of a truss roof for a long-spanbuilding. This study makes use of an innovative hybrid truss that has been developed in a parallelstudy. The project presented herein shows the direct application of the technology on an existingbuilding, emphasizing its feasibility, potentiality and functionality. The paper highlights thecharacteristic of adaptability to both newly designed buildings and existing ones. Starting from thetruss prototype, different shape configurations that the technology allows are hypothesized. Thefinal roof shape is selected based on study aiming at optimizing the elements sections.

The paper deals with the experimental analysis focused on the determination of strain in wooden building structures using optical fibers with FBG sensors. Firstly, optical fibers were used to measure displacements of layers and surface strain of the lower surface of the ceiling panels made from mechanically jointed cross laminated timber (CLT). The measured displacement values of the optical fibers were compared with the results obtained from the inductive displacement sensors. Secondly, optical fibers were used for long-term monitoring of the roof structure of the sports hall. The fibers were mounted on chords of timber trusses and their correct function was verified by a load test.

Protection of historical roof trusses is an important part of efforts to protect our cultural heritage. These timber structures carry a lot of information about used tools, technologies or construction processes. Roof trusses are generally threatened by many dangers, which could cause irreparable damage and loss of the carried information. Wood destroying insects and fungi are the gravest threat to historical roof trusses in our climatic conditions. Their spreading depends on several specific (interior) conditions. These include critical moisture content in the wood, relative humidity, amount of natural light and ventilation. In addition to these commonly monitored parameters (and their critical levels) we also must not forget the influence of local geography, biotope or orientation to the cardinal. This paper describes temporal fluctuations of some of the mentioned physical parameters in a historical roof truss with regard to external climatic conditions and orientation to the cardinal.

The paper provides the analysis of steel truss under fire conditions according to the temperature method. The analysis was carried out for two variants of the fire curves (the standard one, used in traditional approach to fire design and a new one, proposed by the authors, called "exponential" curve). Both curves describe temperature of fire gases but they are obtained using different scenarios. In the case of the standard fire curve, increase in temperature is very rapid in the first minutes and then it decelerates. The exponential curve describes inverse situation: slow increase in temperature of fire gases followed by more rapid one. The fire history defined by the fire curve has great influence on temperature of an element in successive minutes of fire.

In this article, we propose a nonlinear semidefinite program (SDP) for the robust trusstopology design (TTD) problem with beam elements. Starting from the semidefinite formulation ofthe robust TTD problem we derive a stiffness matrix that can model rigid connections between beams.Since the stiffness matrix depends nonlinearly on the cross-sectional areas of the beams, this leads toa nonlinear SDP. We present numerical results using a sequential SDP approach and compare them toresults obtained via a general method for robust PDE-constrained optimization applied to the equationsof linear elasticity. Furthermore, we present two mixed integer semidefinite programs (MISDP), onefor the optimal choice of connecting elements, which is nonlinear, and one for the correspondingproblem with discrete cross-sectional areas.

An analysis of the high building construction has been presented in the paper. Recently high buildings are getting more popular and more common in urban building industry. Moreover nowadays the main trend of the erected constructions is energy saving. Therefore there is necessity to connect these two features. Very helpful for that purpose can be a modern glazing building elevation, which can be used as a solar collectors. For the analysis five different types of high building structures have been taken. As the first analyzed model, core – frame construction with the columns placed on the edge of the building has been considered. In this case the area of glazing surface has been significantly reduced. That is why in a second model, it was decided to move back the columns from the edge, 1.0 meter inside the building. However, for this type of construction, according to obtained results, horizontal displacement of the top of building was greater than allowed by specified standards. In order to fulfill standard requirements and keep a sufficiently large area of glazing, in the third analyzed model extra beams were inserted on the height of 2.5m. In the fourth model added a little truss.

Beams in lightweight truss structures are subject to axial and lateral loads that may lead to undesired structural vibration or failure by buckling. The axial and lateral forces may be transferred via the truss supports that offer possibilities for state control of single beams and larger structures. In earlier own studies, the concept of a piezo-elastic support for active buckling control and resonant shunt damping has been investigated. An elastic spring element is used to allow a rotation in the beam's bearing in any plane perpendicular to the beam's longitudinal axis. The rotation is laterally transferred to an axial displacement of piezoelectric stack transducers that are either used to generate active lateral forces for active buckling control or to attenuate vibrations with a resonant shunt. In this paper, the model verification and validation of the elastic properties of the piezo-elastic support for passive and active structural control of beams with circular cross-section is presented. The rotational and lateral spring element stiffness is investigated numerically and experimentally and the existing models are updated in the verification process. The model is validated by comparing the numerical results and experimental ability for vibration attenuation.

The aim of this paper is finite element presentation for vibration response of the intelligent structure (consisting peizoeectric members) and modification of the response. The active element consists of a piezoelectric ceramic actuator stack, a force transducer and mechanical interfaces. An integral plus double-integral force controller is designed to suppress vibration of the truss. In this paper, in order to find the best piezoelectric operator’s location in spatial truss and optimizing the performance of the member by changing the property of the members, an algorithm is presented to achieve desired natural frequency. Therefore, finite element method of spatial truss is extracted. The results are admitted by ANSYS software. At the end, an example to show the application of the relations is given.

Space solar power satellite (SSPS) as a very large flexible spacecraft structure with complex configuration, large size and number of units bring the difficulties to dynamics modeling and analysis. Considering SSPS structure characteristics, equivalent strain and kinetic energy theory is adopted to establish the equivalent beam model of SSPS truss structure. The assumed mode method is adopted to describe the flexible body. The modal truncation method implements the dynamics system order reduction. Mixed coordinates method is adopted to establish the rigid-flexible coupled dynamic model. The established dynamic model can reflect dynamic characteristics of SSPS, achieve control requirements for SSPS and decrease the workload of simulation calculation. The independent modal space control (IMSC) method is proposed to active control research view of the large displacement, nonlinearity, low and dense mode frequency, light damping of flexible structures. Simulation results on flexible solar array show the effectiveness of the control method.

As transmission tower system has the characteristics of large-span and spatial truss structure, the study of the reliability is also developed on the basis of space truss research and large-span structure system. As simple and suitable, RSM (response surface method), in particular, quadratic response surface without considering the cross term is often used in reliability calculation. However, strong nonlinear limit that corresponding to a complex surface, the accuracy of quadratic response surface is inadequate, causing greater reliability estimation error. High-order response surface solves it well. To this end, based on univariate analysis of multivariate function, a reasonable algorithm as to assure that the form of higher-order response surface is proposed; on the algorithm is verified by given examples, the result shows better accuracy and efficiency .

In the present paper, the Preisach model of hysteresis is extended to structural analysis of trusses damaged under cyclic loading in plastic range. Parameters for the Preisach model of cyclic plasticity are obtained from uniaxial loading experiment. Damage, as a consequence of micro cracks appearance due to alternating loading in plastic domain, is modeled using brittle elements according to Preisach procedure. Results of this research are compared with the already existing in the literature. In the paper examples of trusses under various cyclic loadings are presented. Applied Mechanics and Materials

This paper presents the study of failure surface obtained in the truss-like Discrete Element Method (DEM). The element constitutive law considers the fracture energy of the material and its spatial variation is used to take into account the heterogeneity of the simulated materials. It is studied the influence of spatial distribution of fracture energy and the spatial lattice perturbation on the DEM failure surface. A DEM failure criterion is compared with concrete and rock failure.

This paper deals with the design optimization, static, modal and probability analyses of a simplified space truss, which was used to cover a festival square. Design optimization was used to achieve the best parameters for steel tubes of 3-D lattice plate. The results from two optimization methods were compared and finally modal analysis was performed with best parameters giving the own shapes and own frequencies. For the deterministic analysis the Monte Carlo simulation was used. Finally some results are presented.

Von Misses truss is one of the best examples to explain nature of non-linear solution and define the snap-through. Linear buckling analysis and nonlinear finite element approaches are compared in presented paper. At the present time theoretical models for the evaluation of the ultimate load assume a structure with imperfections. The peculiarities of the effect of the magnitude and mode of initial imperfections are investigated. Effect of member stiffness on the load level in critical point of nonlinear solution, as well as the relative position with respect to the critical load from buckling analysis are analyzed. To obtain the nonlinear equilibrium paths, Newton-Raphson iteration algorithm has been used. Obtained results are compared with those gained using ANSYS system.

The article deals with the computational model of an elastic von Mises planar truss. The description of a mathematical concept, which is intended for the creation of computational programmes based on a finite number of segments, is presented. The mathematical solution is suitable for the analysis of load-deflection curves. Structural deformation is evaluated by seeking the minimal potential energy. The article examines the effects of change in the vertical displacement of the top joint on strut axes. The step by step incremental method is used in combination with the Newton-Raphson method. The presented study is aimed at the evaluation of the force in the bifurcation point, which determines the moment when loading of the model causes passing from the pre-critical effect (attainment of maximum vertical load action) to the post-critical effect. Symmetric and asymmetric initial axis imperfections are considered and relevant symmetric and asymmetric shapes of buckling are identified. The stability problem of the von Mises truss is discussed in connection with the random effects of imperfections.

Method of searching for rational shapes of skeletal structures based on the use of Delaunay tetrahedron partition algorithms with constraints and evolutionary modeling has been developed. Topology of load-bearing rod system is synthesized on specified multitude of nodes at fixed number of rods. Established structures are considered redundant and are optimized by means of excluding individual members. Optimization is performed with the modified genetic algorithm pursuant to criterion of minimum weight of structure. An example of synthesis of rectangular rod structure showing performance of suggested approach in terms of shape synthesis of trusses has been given.

Parallel welded steel truss component is widely used in construction, tower, bridges, aerospace and other fields. And the welding residual stress is distributed complicatedly in many areas and directions, which will definitely deform the welded steel truss or even crack it. So, it is necessary to do aging treatment to avoid such thing happened, as well as improve the accuracy and reliability. Vibratory stress relief (VSR) is a new kind of technology which may eliminate the residual stress in metal component with high efficiency, energy-saving, environment protection and low cost compared with thermal stress relief (TSR). But its technical effects vary with the vibration parameters. To the parallel steel truss structures, the excitation parameter of VSR is determined by welding residual stress distribution and the natural mode of vibration. The residual stress concentration areas can get enough vibration, if the parallel steel truss component vibrates with different kinds of natural mode of vibration, which will obtain good effect of eliminating stress. Firstly, the inherent vibration mode of parallel welded steel truss component is measured by the modal analysis technology. Secondly, multiple intrinsic modes are chosen according to principle of making all the welding residual stress concentration regions and directions get enough vibration and then main technical parameters are determined such as excitation frequency, excitation point and support point. In this paper, two examples are given out: the specimen 1is treated with the transverse bending vibration mode and torsion vibration mode respectively according to the above method. As for specimen 2, it is treated with 3 exciting frequencies which are located automatically by the vibration aging machine. The residual stresses of the two specimens are measured before and after their vibrations with blind holes method. Results show that after vibration aging, the welding residual stress peak figure of the Specimen 1 is reduced by an average of 48.65% and the mean value of that dropped by an average of 32.50%. Correspondingly, the residual stress peak value of the Specimen 2 shows a decline of 3.38%, its average fell by an average of 2.55%.

This paper analyzes the reason of a steel truss building which collapsed under a snow disaster. Firstly, the investigation and inspection in site are introduced. Secondly, based on the on site work, such as the property of the metal materials and the quality of the welding joint, the status of the structure is comprehensively determined. Thirdly, through calculation with the former results, the reason of the collapse accident is obtained. Finally, some related suggestions are proposed for the design and construction of this kind of structure.

The truss is widely used as a loaded platform in many fields and industry. The structure strength and stability analysis on the truss is researched under the operation of lifting in the paper. Firstly, the additional water gravity load is considered and calculated, which cannot be pushed out of rods during the process of lifting up from deep sea. Then the finite element model based on ANSYS/WORKBENCH software platform for the truss is created, and the boundary conditions and payloads are set into the model. Lastly, the structure strength is checked and the stability analysis is proved based on the FEM method. The results in the paper verify effectively that the strength and stability of truss under the lifting operation meet material and structure performance requirements, thus the research in the paper is of significant reference on the safe service and engineering application for truss.

Based on the characteristics of space truss structures, the concept of modal strain energy is introduced and square difference in elemental modal strain is presented. Through the square difference in elemental modal strain and wavelet transform, this paper presents a method for space truss structure damage recognition. The structural damage index is presented with the change of wavelet coefficients. Numerical simulation results show that: this method is effective to locate the single, multiple damages and light, severe damage with the first mode information. The preliminary tries for damage extent identification were made by the wavelet coefficients.

The QTT (QiTai 110m radio telescope) antenna, with large aperture and high main-reflector surface precision, whose connecting strategy between back-up structure and alidade was investigated. In order to make the reflector surface deformation coordinated, the connecting strategies of “umbrella supporting”, “space truss” and “double gear” structure were constructed and analyzed based on FEM (finite element method). The results show that “double gear supporting” is superior to “space truss structure”, and the latter is better than “umbrella supporting”, while in the “umbrella supporting structure”, the smaller cone angle is good for reflector deformation coordination. These structures are easy to achieve antenna structure “homology” design.

This paper presents the test of 3 reinforced concrete pile caps and the complete procedure of failure as well as the stressed mechanism, including the description of the occurrence of cracks. The influences of reinforcement types on load-bearing capacity are also probed. A spatial truss model is put forward and can explain satisfactorily some phenomena observed in the test and the failure mechanism is investigated.

Space trusses are three-dimensional structures made of steel bars very frequently used at the roof construction. The bars, with tubular section, are linking in the 3D form by connections. There are several types of connections to attach these members. The most economical connection is the staking end-flattened connection, also called typical node. The reduced cost and the fast assemblage of the truss are among their advantages. However, such connections present disadvantages like eccentricities and stiffness weakening of the tubular members. This research presents suggestions of reinforcement and constructive correction in the connection in order to increase its capacity. The base for this is the reduction of the eccentricity in typical node applying the spacer. This spacer was made by polymer composite with sisal fiber. In this work was developed experimental lab tests in prototypes with fifty four meters square of area. The results show an increase of 26% for collapse in the truss load carrying capacity when the suggested changes proposed in this article are used for the staking end-flattened connections.

A method based on the square difference of elemental modal strain was proposed to determine the damage location and damage degree. The square difference of elemental modal strain was expressed damage before and after. Simulation results show that: this method is effective to locate the single, multiple damages and light, severe damage with low-order modal information. Damage degrees can be initially determined by the values of the square difference of damaged-element modal strain. Furthermore, the result also shows that this method can accurately identify the damage location of plane truss structures with noise.

Standardization and unification of elements, constructions and design solutions is one of the main ways to reduce the complexity and cost of the construction.Standard designs of truss coatings with a 10% slope for 24, 30, 36 meters spans were developed in this article for different load combinations.Stress calculation and truss elements dimensioning was made with the SCAD Office software complex. Then the relationship between the thickness of the section, span and load was defined, and the limits of various sizes of the accepted bottom chord connecting block.Designed series of truss structures with a 10% slope and 24, 30, 36 meters spans covers a range of line loads from 1,3 t/m to 3.3 t/m. In comparison with the truss structures series Molodechno it has a lower metal consumption by reducing the cross section of the upper chords due to vertical elements adding. Transportation of a 12-meter section falls under the category of oversized transportation.

The Long girder end parts are one of the types structure in aerospace equipment, the complex structure parts, machining parts. Usually the parts be processed on the NC milling machine, through the analysis of processing craft, design a kind of quick change type, Multi-station clamp device, instead of processing the parts on the multi-axis nc machine tool; at the same time of guarantee machining accuracy, in order to improve the production efficiency and reduce the cost of production.

The paper presents fundamental principles and application of the large-scale truss structure PKP25-20i optimal design based on a multi-criteria optimization algorithm. The multi-objective function contains conditions for deformation, stability and cumulative damage obtained by finite element analyses. The whole process was implemented and realized in special Matlab’s procedures and FEM software Cosmos/M.

The effects of large-span truss geometry of the double-plane stable orthogonal design. The use of finite element analysis software Midas double space truss were linear buckling analysis and nonlinear buckling analysis, research process and through its buckling load - examine issues outside of the structure of the plane stable displacement curve. For double truss draw some outside reference plane stability study conclusions.

Cross sectional areas optimization is to be implemented to study the influence of the cross section shape on the optimum truss weight. By the aid of analysis and design engines with advanced finite element analysis that is the steel design software STAAD. Four rolled steel sections (angle, tube, channel, and pipe) which are used in industrial roof trusses are applied for comparison. Many previous studies, use the areas of cross sections as design variables without highlight to the shape of cross section at the start of the process, consequently the result area will be adequate if the designer choose the effective shape than others. Results of this research show that the chosen cross section shape has a significant impact on the optimum truss weight for same geometry of truss type under the same circumstances of loading and supports.

A method which utilizes Kriging model and a multi-point updating strategy is put forward for solving expensive multi-objective optimization problems. Assisted by a defined cheaper multi-objective optimization problem and a maximum average distance criterion, multiple updating points can be found. The proposed method is tested on two numerical functions and a ten-bar truss problem, the results show that the proposed method is efficient in obtaining Pareto optimal solutions with good convergence and diversity when the same computation resource is used comparing with two other methods.

The truss structure has characteristics of small mass with high rigidity etc., so it is still practical in structures and researched by engineers and scientists. Here a truss structure with the paraboloid top surface is presented; several truss forms of the octahedral space units are connected into it. The equilibrium matrix is calculated by the force-density method. From the equilibrium matrix, number of the self-stress mode and number of the displacement mode of the structure is calculated. According to the obtained result, the structure is proved to be in equilibrium. Through the ANSYS software, the truss structure is researched for deformation under outer forces and it is proved that the structure has certain rigidity and withholding capacity.

In terms of structure design for transmission towers, early because of restricted by calculation method, are generally will tower inner force analysis that was decomposed into several pieces of plane truss. This method omits truss space effect, is a kind of approximate calculation method. Later adopted a more accurate method of space truss, considering the relations between the deformation coordination of bar of tower structure and the mechanical equilibrium conditions, can reflect the actual situation of the tower stress relatively and accurately. The above calculation method, both plane truss method and method of space truss all nodes are assumed to be the ideal of articulated point, ignoring the interaction of the influence of secondary moment and torque to the structure. In recent years, with the rising of power grids, high voltage, large capacity of transmission lines construction become the trend of the development of the grid technology. Gradually to develop in the direction of high, long-span transmission tower, component cross section increases gradually, the second-order stress effect on the structure is becoming more and more important. The truss method in some special structure and the adaptability of complex working conditions should be tested by experiment and other finite element calculation software review.

The characterization and design of photovoltaic systems is a difficult issue due to the critical step in shell configuration. It is important in analyzing structure system with finite element method for complex truss structure. This paper proposes a new model to develop an availability framework for photovoltaic generation. The proposed technique can be applied to the analysis of calculation of photovoltaic modules and photovoltaic atmospheric conditions.

Wuhan Tianxingzhou Yangtze River Rail-cum-Road Bridge is the first four line rail cable-stayed bridge in china, with three-truss cross section. The new structure presents complex load performance, especially the spatial mechanical characteristics, because the bridge supports six lanes and four railway load, inevitably the main truss will produce a great torque, leading to three-truss cross section distortion and warping deformation. Analysis of the whole bridge spatial structures is carried out. The space shear flexible beam grillage model is used for bridge structure simulation, the upper and lower vertical member and the horizontal link simulated with beam element, while the pylon with space beam element, the cable with cable element. Though the calculation of the cable force and stress, the main girders stress, the pylon stress, the displacement of the main girder and the pylon, it can be shown that the space force and displacement keep within the standard requirement.

A closed coal yard grid’s tructure is the shell and tube bolt ball grid, larger span, rise high higher, the highest point to ground is very high. This space truss’s construction method uses slice installation and aerial bulk construction method. Use Midas Gen 8.0 software to calculate and analyze the whole structure of the grid construction, simulate the construction process, calculate the rod deflection and stress values, the calculated results meet the regulatory requirements. This paper provide some reference for future similar projects.

It is introduced that three main factors cause geometric nonlinear effects of long span cable-stayed bridge: large displacement effect, cable sag effect, and the combination of bending moment and axial force effect. The iteration method of geometrical nonlinear problem is also introduced. The bridge deformation was calculated by establishing a plane truss finite element model of a long-span single tower cable-stayed bridge under consideration of nonlinearity and compared with that done with linear method. It is concluded that nonlinearity influenced differently to the bending moment of main girder, the displacement of tower root and the vertical displacement of girder.

This article takes the composite wall slab that be connected by reinforcing bar trusses as an example, research the method and steps of calculating the carrying capacity of precast concrete composite heat-insulation wall slab.Finally,The equation for calculating the carrying capacity of precast concrete composite heat-insulation wall slab is obtained by theoretical analysis and finite element modeling, this provide a basis for how to use the composite wall safely in engineering.

More than 40 prestressed composite space truss models of different dimensions are built with APDL design language, and the span, height, lattice number, prestressed value, section area of the chord, width and height of ribbed beam are chosen as design variables. With selecting total cost as objective function, constraint conditions such as strength, rigidity, stability, section size, prestressed limit and structural deflection are also considered, we conduct optimal design for structures by means of zero order optimization. From the results of regression analysis, the optimal span-to-height ratio, lattice number and empirical formula of optimal prestressed value can be found out for designers’ references.

While many researchers have investigated the dynamics analysis of underactuated mechanisms in recent years, little work has been published on that with underactuated cable-truss mechanism. Dynamics analysis has important significance in the research of trajectory planning, driven project designing and the optimization design of the mechanisms. The mechanism dynamics equations were established based on Lagrange equation and the dynamics equations corresponding to the capture scheme that has been chosen were separately listed. To prove the correctness of the dynamics analysis, the simulation of the capture scheme was presented. Some capture experiments were done in order to verify the adaptive capture function of the underactuated cable-truss mechanism.

The design flow of deployable support structures is proposed based on modal analysis, and the finite element model for DST of satellite SAR is researched. On these bases, the affecting factors of DST attitude fundamental frequency (f1) and mass, such as geometry parameters, the lock position, stiffness of hinges and thickness of truss links, are analyzed and optimized. Lastly, considering of space thermal environment the optimal design of the DST is meted the requirements under different thermal fields. The research results are of great importance to improve the performances of DST.

In this paper, some popular software, such as structural mechanics solver, ANSYS and SAP2000 are used to calculate the deformation of truss structure under statics loading. This deformation can also be handy calculated by the principle of virtual work of structural mechanics. By comparing the calculated results with the experimental data, we can test the accuracy of these methods, especially when the joints in a truss structure are modeled as hinge joints or rigid joints. The calculated results show difference of the different modeling is very slight. The accuracy of hand computation is also satisfied compared with the results of software.

The globally convergent version of MMA (GCMMA) is deeply studied in this paper. Based on 3-bar truss structures, the advantages and disadvantages of the rules for updating the parameters are analyzed. The factor that makes convergence rate slow is found. Then the improvement measure by using two points approximate optimization for reference is put forward to speed up convergence rate. Finally by application on structural optimization of a truss, improved GCMMA can converge to the global optimal solution. Meanwhile, the convergent rate of improved GCMMA is significantly faster than GCMMA.