Stress Analysis of Laminated Composite and Sandwich Beams using a Novel Shear and Normal Deformation Theory

Abstract

A novel Normal and Shear Deformation Theory (NSDT) for analysis of laminated composite and sandwich beams, taking into account shear deformation as well as normal deformation, is developed. The paper investigates flexural behaviors of thick laminated and sandwich beams under plane stress conditions using NSDT. A generalized displacement-based refined formulation is elucidated with inclusion of various warping functions in terms of thickness coordinates to represent shear and normal deformation effects. These effects become pronounced in thick laminated beams and particularly in sandwich beams with transversely flexible core. Present formulation satisfies the shear stress free surface conditions at the top and bottom surfaces of the beam with realistic through-the-thickness variation of transverse shear stresses. The results obtained are compared with higher order theories available in literature. It is observed that NSDT predicts displacement and stresses accurately compared to other higher order theories. K eyw ords: Shear deformation, transverse flexibility, laminated thick beam, sandwich beam, transverse shear stress.

Flexural analysis of laminated composite and sandwich beams using a four-unknown shear and normal deformation theory

“…It should be noted that normal and shear deformation effects are included in these studies with different models. Again, excellent agreement with previous studies can be observed, especially with those from Pawar et al [20]. As beam gets thinner, the present results agree well with those of Carrera et al [29] for various boundary conditions.…”

“…They have not been reported before and could be served as benchmark examples for future references. The results are also compared with those from Kant et al [19] and Pawar et al [20] and Carrera et al [29]. It should be noted that normal and shear deformation effects are included in these studies with different models.…”

“…Pawar et al [20] derived Navier solution for static analysis of cross-ply composite and sandwich beams.…”

Predicting the Response of Laminated Composite Beams: A Comparison of Machine Learning Algorithms

“…In the FOBT, a constant state of transverse shear strain is assumed that does not satisfy the zero shear stress condition at the top and bottom edges of the beam and thus requires a shear correction factor to compensate for this error (see, e.g., Wang et al, 2000;Eisenberger, 2003;Civalek and Kiracioglu, 2010;Lin and Zhang, 2011;Endo, 2016). In general, the HOBTs adopt a specific function (parabolic, trigonometric, exponential, or hyperbolic) to more accurately represent the shear stress distribution along the beam's thickness and do not require the shear correction factor (see e.g., Reddy, 1984;Heyliger and Reddy, 1988;Khdeir and Reddy, 1997;Murthy et al, 2005;Vo and Thai, 2012;Pawar et al, 2015;Nguyen et al, 2017;Srinivasan et al, 2019). The literature contains a plethora of publications on the subject, and the interested reader is referred to the excellent review paper of Liew et al (2019).…”

Kompozi̇t Eğri̇sel Ki̇ri̇şlerde Kesi̇t Çarpilmasi Gözeti̇lerek Normal Ve Kayma Geri̇lmeleri̇ni̇n Karişik Sonlu Elemanlarla Anali̇zi̇

“…Carrera bileşik fonksiyonu ile tabakalı kompozitlerin normal/kayma gerilmeleri elde edilmiştir [24]. Kompozit kirişlerin normal ve kayma gerilmeleri için normal ve kayma deformasyon teorisi geliştirilmiştir [25]. Dik açılı kompozit kirişlerin kesit boyunca normal ve kayma gerilmeleri için yüksek mertebeden kayma deformasyon teorisi önerilmiştir [26].…”