Papers by Keyword: Truss Structure

Abstract: 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.

Abstract: 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.

Abstract: With the development of national economy, space structures of great spans develop quickly. The architectural modelings update, structural systems diversify and structural spans gradually expand. So the study on space truss structure under different specific conditions has great significance upon the security, the proper use and reducing cost.

Abstract: In this study, a two step damage prognosis method is proposed for beam-like truss structures via combining modal curvature change (MCC) with modal strain energy change ratio (MSECR). Changes in the modal curvature and the elemental strain energy are selected as the indicator of damage prognosis. Different damage elements with different damage degrees are simulated. In the first step, the finite element method is used to model a beam-like truss structure and the displacement modes are got. The damage region is estimated by the MCC of top and bottom chords of a beam-like truss structure. In the second step, the elemental MSECR in the damage region is calculated and the maximum MSECR element is deemed as the damage element. The simulation results show that this method can accurately locate the damage in the beam-like truss structure.

Abstract: Due to the fatigue load and bad corrosion environment, truss structure in service will form the damage accumulation, damage detection of potentially damaged elements of truss structures is a challenging topic. According to the element stress characteristics of truss structure, structural element strain mode mainly based on the vibration displacement is derived, the change of elemental strain modal is proposed as the dynamic indicator for damage location identification of truss structure. Based on the numerical simulation study of the actual truss structure indicates that, the loworder elemental strain modal method is not only sensitive to damage identification of chord element and web element of truss structure, but also is effective to locate the damage of different position, and is suitable for damage alarming of truss structure in service.

Abstract: By using the intrinsic character of the truss structure, a new direct damage identification method of the truss structure based on residual force vector is presented. The stiffness connectivity matrix is got by sensitivity analysis, and it can be used to expand the stiffness perturbation matrix of damage structure, then, a new residual force vector is got, it can be solved directly, so the stiffness perturbation of structure is got, by it, the damaged locations and the extents of the truss structure are identified. At last, a hyper static truss structure example is given, the identification result shows that, only needed the first-order mode of the damaged structure, the damage can be identified accurately.

Abstract: Based on the minimum mass as optimal objective function, it sets up an FE model of the truss structure. The Multi-Island Genetic Algorithm (MIGA) and NLPQL are adopted as the optimization policy. Experimented with a truss walking platform as an example the validity of the methods was proved. The results showed that the NLPQL can get better optimal solutions of structure and reduce the mass effectively. It has important theoretical value and practical engineering significance.

Abstract: Based on the background of rotary platform of launching tower ,the continuum method based on rigidity equivalent principle and mass equivalent principle is used to transform the truss structure to an uniform solid cantilever beam rotating around its edge ,which makes the vibration equations establishment with methods of parameter supposition and numerical analysis possible . The agreement of the calculation results and the test results means method of this paper available in the vibration analysis of cantilever truss structure .

Abstract: based on the structural characteristics of the truss structure, the mathematical model design model for a truss structure used in Mast-climbing Work Platform is built with Ansys design language, in which the maximum stress is the optimization objective and the bar orientation is the design variable, showing the constraints and loading condition in mathematical matrix expression, on this premise of the stiffness condition meets the requirement, the bar orientation brings about great influence on the truss structure optimizing, the triangular framework optimized to be quadrangle framework, the maximum stress has been decreased by 74.37%.

Abstract: Abstract: The material parameters and the load are considered interval uncertainty and regarded as interval variables in this paper. The interval finite element analysis model is established for engineering structures. The interval parameter perturbation method and endpoint combination method based on monotonic are used to calculate deformation range. Sensitivity on the material parameters and load is studied.as an example for truss structure, the conclusion is more reasonable and applicable.