Papers by Keyword: Beam

Abstract: Application of optimization method for structure design and analysis is a technology trend to provide optimum products. This paper describe optimization process using genetic algorithm that was applied on non traditional structure, geodesic beam element. Finite element method program was developed as a main computer code for supporting optimization process. Pre-and post processor program was created to support GA. Based on minimum structure weight as the target of design optimization, the number of beam, beam element angle, and its size are to be the output of optimization process. The geodesic structure weight of plane model have been compared with traditional structure, and the results show that geodesic structure provide better performance of responding load direction than traditional structure. The influence of swept angle to the weight structure show that the higher the swept angle of geodesic beam structure, the higher values of weight structure are resulted.

Abstract: This article is focused on GLULAM (glued laminated timber) beams and determination of their properties by using non-destructive method. This text is mainly focused just on part of more complex research of glued laminated timber beams. This text is focused on non-destructive method, which is the method of spike that uses device called Pilodyn 6J for measurement. Results of this method are in form of Young ́s modulus of elasticity. This article will describe how the method of spike works, with basic description, describes the tested material and compare the results of testing. In the conclusion we discuss the results, make conclusions and describe the way of our further research of glued laminated timber beams.

Abstract: This paper resolved CNC turret punch cause vibration phenomenon in the course of processing sheet,analysis of its dynamic characteristics of the beam servo feed mechanism, using the method of constrained modal analysis.Through the establishment of finite element model exactly for the servo beam and setting the boundary elastic restraint stiffness, solving the natural frequencies and mode shapes of the servo beam under boundary constraints and loading conditions. Constraints modal analysis results are consistent with experimental monitoring results of CNC turret punch servo beam. This modeling methodology and results of the analysis has a high practical value for CNC turret punch dynamic characteristics analysis and structural optimization design.

Abstract: 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.

Abstract: The article deals with the modal analysis as a tool for specification of natural frequencies and the mode shapes of the turning tool. This type of analysis is the first step that is necessary to do at the dynamic analysis of technical components. At the beginning, the verification of numerical method was realized in laboratory conditions, where the fixed beam substituted the turning tool. Vibrodiagnostics of the real cutting tool in the workshop and the modal analysis using FEM in the software PTC Creo followed. It can be said that the results of the numerical method based on FEM were comparable with the data achieved by means of experimental measurements. The work described in this paper can be considered as a foundation for the dynamic tool life analysis.

Abstract: The goal of the paper is to model and evaluate the total load capacity of the reinforced concrete beams. A non-linear analysis and finite element method were used for that purpose. The model consists of 3D finite elements. The constitutive model of concrete for the non-linear analysis is based on a fracture-plastic theory. The input parameters are the data obtained in previous tests which included both standard tests and additional tests of the testing bodies. There is no shear reinforcement in the beams. The non-linear calculations were carried out for several variants. The study takes into considerations the influence of concrete properties as well as the size of the finite elements.

Abstract: This article presents paper deals with experimental verification of defect’s influence on the beam structures’ eigenfrequency extraction performed numerically with the ABAQUS Finite Element Analysis (FEA) software. The results for beams with defects were compared to those obtained for their undamaged (healthy) counterparts. The beams were made of aluminum and of a laminated glass-epoxy composite. The experiments confirmed the numerical results both quantitatively and qualitatively showing also some differences between the two materials.

Abstract: To investigate the dynamic behavior of beams with partially delaminated layers, a model is presented in this work. This model takes into account the lateral strains. The principal advantage of the element is that it allows the modeling of delamination anywhere in the structure. The region without delamination is modeled to carry constant peel and shear stresses. Numerical results of the present model are presented and its performance is evaluated.

Abstract: Rubbercrete is a concrete containing crumb rubber as partial replacement to fine aggregate. Advantages of rubbercrete have been reported by many researchers. In contrast to normal concrete, rubbercrete is a more ductile which can be used in areas prone to earthquake. In this paper seven reinforced rubbercrete beams without shear reinforcement are fabricated and tested up to failure. Three parameters are considered: beam width, effective depth and a/d. The experimental results are then compared with available shear quations. Available shear quations have produced conservative shear stress prediction for the reinforced rubbercrete beams.

Abstract: In the normal practice in the reinforced concrete design, the main reinforcement steel bar and links was used to fabricate the concrete structure. However new materials such as steel fiber has been introduced as the reinforcement to the reinforced concrete structure [1]. Nowadays, the application of fiber in concrete increase slightly as an engineering material demands. Fibers have distinctive of geometry, size and material. The characteristics and properties of fiber influence the properties concrete. Steel, glass and synthetic fibers were used in concrete in 1960s because of the difficulty to handle the asbestos fiber [2].