The topic of smart structures, their active control and implementation, is relatively new. Therefore, different approaches to the problem can be met. The present paper discusses variable aspects of the active control of structures. It explains the idea of smart systems, introduces different terms used in smart technique and defines the structural smartness. The author indicates differences between actively controlled structures and structural health monitoring systems and shows an example of an actively controlled smart footbridge. The analyses presented in the study concern tensegrity structures, which are prone to the structural control through self-stress state adjustment. The paper introduces examples of structural control performed on tensegrity modules and plates. An influence of several self-stress states on displacements is analyzed and a study concerning damage due to member loss is presented.
In the present paper tensile stresses perpendicular to the grain in reinforced double-tapered beams made of glued laminated timber are discussed. The beams are analysed using the finite element method within the linear elasticity theory with the influence of orthotropic material properties. The main objective is to assess the influence of transverse reinforcement on the values and distributions of the analysed stresses and to identify the most efficient scheme of reinforcement. The obtained results prove that, with the use of the proposed tools, it is possible to assess the level of stress, including delaminating stress, and to indicate the areas of occurrence of such stress with high precision.
The present paper discusses static and dynamic characteristics of various under sleeper pads (USP) that are to be used in the ballasted track systems as resilient vibroacoustic isolators. Four different USP samples were put to fatigue tests and static and dynamic bedding moduli were determined. The purpose of the tests, which were carried out up to 500 thousand load cycles, was to determine which USP have favourable and which unfavourable properties, taking into account their potential application as the elements used for energy dissipation and reduction of noise and vibration. The obtained results allowed the authors to indicate samples with a potential for further analysis and to reject those, which did not satisfy the adopted criteria.
The present paper is dedicated to the analysis of deployable tensegrity columns. The main aim of this work is to present a technique, developed by combining the finite element (FE) analysis and the multibody dynamics (MBD) simulation, which enables precise and reliable simulations of deployable structures. While the finite element model of the column provides information on structural behavior in the deployed state, the dynamical modeling allows to analyze various deployment scenarios, choose active cables for the deployment and for the self-stress application, and to control distributions of internal forces during the assembly process. An example of a deployable column based on a popular tensegrity module – a 3-strut simplex – is presented. By analyzing the proposed column with the use of the developed method it is proven that the technique is suitable for complex simulations of deployable systems.