China
Africa
Explore chapters and articles related to this topic
Fundamentals of Collision Actions on a Structure
Published in Arnold C.Y. Yong, Nelson T.K. Lam, Scott J. Menegon, Collision Actions on Structures, 2023
Arnold C.Y. Yong, Nelson T.K. Lam, Scott J. Menegon
In the case of a collision on a free-standing object, which can be a portable barrier, the kinetic energy delivered by the impactor can be dissipated in the form of sliding or overturning, or both, depending on the geometry of the barrier and the ground conditions (Figures 3.1(a) and (b)). In the case of a structure that is restrained at its base to prevent sliding or overturning, the kinetic energy has to be absorbed by the structure in the form of strain energy. Slender structures, such as a pole or a barrier wall, develop strain energy associated with bending/flexural actions (Figure 3.1(c)). For a low-intensity collision where no damage occurs, all the energy can be dissipated through damping over the duration that the structure is left to vibrate freely. This chapter deals with the bending of a structural element responding to a collision. The sliding and overturning behaviour of a free-standing structure is presented in Chapter 4.
Simple Elements
Published in Steven M. Lepi, Practical Guide to Finite Elements, 2020
Even though plates and shells are relatively thin, structures modeled with these types of idealizations can take on a vast array of shapes and sizes. In addition, beams, plates, shells, and solid elements may be combined within a given model to characterize a wide range of structures.17 The first structural element to be considered in this section is a simple 2-node line element for beam bending applications.
Introduction to Design of Composite Structures
Published in Robert M. Jones, Mechanics of Composite Materials, 2018
Using a honeycomb laminate, i.e., having some kind of a lightweight core like the honeycomb in a bees’ nest inside the outer layers of the laminate, is typically a way of increasing the bending stiffness of a structure with very little increase in weight. That is, we could use a very thick laminate, which is heavy, to do the job, or we could get the same bending stiffnesses with a laminate that has two sets of thin laminates, one at the top and one at the bottom, with a shear-deformable core bonded in the middle of the two laminates. Such a structural element has very high bending stiffness. The honeycomb-core laminate is, of course, thicker, but lighter than the monocoque laminate with equal bending stiffness. We also can use honeycomb cores with metal structures, in which case we have actually created another form of composite structure! Honeycomb is often placed inside many aluminum structures, so that approach is quite common.
Bird strike assessment for a composite wing flap
Published in International Journal of Crashworthiness, 2018
S. Orlando, F. Marulo, M. Guida, F. Timbrato
Some emphasis has been devoted to the materials, which are deputed to absorb high level of kinetic energy. These materials, as in the case of bullet impact, can dissipate the kinetic energy involving a small portion of the target. Composite materials are widely used in the aircraft industry, both for primary and secondary structures; the materials devoted to absorb high-level energy, in particular the impacts due to rain, birds and hailstones, are differently dealt in correspondence of the involved structural element.