Linear viscoelastic analysis of straight and curved thin-walled laminated composite beams

Abstract

This paper is devoted to study the behavior, in the range of linear viscoelasticity, of shear flexible thin-walled beam members constructed with composite laminated fiber-reinforced plastics. This work appeals to the correspondence principle in order to incorporate in unified model the motion equations of a curved or straight shear-flexible thin-walled beam member developed by the authors, together with the micromechanics and macromechanics of the reinforced plastic panels. Then, the analysis is performed in the Laplace or Carson domains. That is, the expressions describing the micromechanics and macromechanics of a plastic laminated composites and motion equations of the structural member are transformed into the Laplace or Carson domains where the relaxation components of the beam structure (straight or curved) are obtained. The resulting equations are numerically solved by means of finite element approaches defined in the Laplace or Carson domains. The finite element results are adjusted with a polynomial fitting. Then the creep behavior is obtained by means of a numerical technique for the inverse Laplace transform. Predictions of the present methodology are compared with experimental data and other approaches. New studies are performed focusing attention in the flexural-torsional behavior of shear flexible thin-walled straight composite beams as well as for thin-walled curved beams and frames.

Comportamiento al creep de un polímero utilizado para impresión 3D

“…Se observa que las probetas con disposición a 45º respecto del eje de tracción tienen una deformación que llega a superar, dentro de la etapa secundaria de creep, en más de 5 veces la correspondiente de las probetas con disposición de filamentos co-lineal al eje de tracción. Este comportamiento tiene un cierto paralelismo con el homónimo problema de materiales compuestos laminados de resinas reforzadas por fibras y su uso en estructuras [6]; puesto que la disposición de fibras en ángulo con respecto a la dirección de forzamiento tiene una menor resistencia mecánica y por ende mayor tendencia a deformación que su contraparte co-lineal al forzamiento. Aun así se debe destacar que construcciones en capas hechas por impresión 3D no son en esencia semejantes a las de materiales compuestos laminados puesto que estas últimas poseen matriz resinosa y las primeras no.…”

Theoretical and Experimental Analysis of Thin-Walled Curved Rectangular Box Beam under In-Plane Bending

“…However, previous literature has made assumptions regarding deformation theory, the rigidity of the section, and the effect of curvature, in the above articles on thin-walled curved beams, whether in finite-element analysis, linear viscoelastic analysis [ 12 ], one-dimensional high-order theory [ 13 ], or cross-section deformation mode analysis [ 14 , 15 ]. In theoretical analysis, the analysis is always predictive, regardless of its accuracy.…”

A study of crack‐fiber interaction in fiber‐reinforced composites using optical caustic method

“…Fiber‐reinforced composites are widely used in many engineering structural fields such as aviation, mechanical engineering, maritime engineering, and civil construction, both for structural and nonstructural members, because of their high strength‐density ratio, high stiffness‐density ratio, good corrosion resistance, and long fatigue life . The addition of fibers usually confers multiple benefits to the matrix polymers, e.g., increase in modulus and tensile strength, better dimensional stability after processing and often enhanced fatigue resistance, especially on the fracture behavior.…”