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A structural beam which is subjected to shear forces acting perpendicularly to its longitudinal axis will experience longitudinal and transverse shear stresses. In beams where failure in the transverse direction is plausible, it is desirable to maintain a constant transverse shear stress over the beam cross-section to avoid stress concentrations an...
Contexts in source publication
Context 1
... longitudinal shear strength of the beam acts as the agent by which the slip between layers is prevented [7,8]. The transverse shear stress í µí¼ varies along the cross-section of a beam as shown in Figure 2, where í µí¼ is the maximum transverse shear stress and í µí±í µí°ís the neutral axis, or the centroid of the cross-section [7]. For the rectangular cross-section shown in Figure 2, the solution is easily derived as a parabolic transverse shear stress distribution which has zero shear stress at the top, peaks at the neutral axis and returns to zero at the bottom [8]. ...
Context 2
... transverse shear stress í µí¼ varies along the cross-section of a beam as shown in Figure 2, where í µí¼ is the maximum transverse shear stress and í µí±í µí°ís the neutral axis, or the centroid of the cross-section [7]. For the rectangular cross-section shown in Figure 2, the solution is easily derived as a parabolic transverse shear stress distribution which has zero shear stress at the top, peaks at the neutral axis and returns to zero at the bottom [8]. The resultant shear force produces longitudinal and transverse shear stresses shown in Figure 3. ...
Context 3
... stresses must be equal to each other to maintain the equilibrium of an infinitesimal stress element which is located at any theoretical point in the beam [7]. It should be noted that í µí¼ is equal to zero at the top and bottom of the beam, shown in Figure 2. This is due to the fact that the top and bottom boundaries of the beam are exposed to air and therefore carry no longitudinal load [7]. ...
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... is due to the fact that the top and bottom boundaries of the beam are exposed to air and therefore carry no longitudinal load [7]. It can also be observed in Figure 2 that the maximum transverse shear stress occurs at the neutral axis. Though this is not always the case, it can be derived that the maximum transverse shear stress will always occur at the neutral axis if the cross-section of the beam is thinnest at that point [7]. ...
Citations
... However, the main failure mode in the thicker samples, i.e. 9-mm-thick sample and 10-mm-thick samples, was interlaminar delamination from the notch area all the way to the end of the samples. The delamination was probably caused by the large transverse shear stress induced by the larger thickness of the sample because the transverse shear stress increases with increasing number of composite layers or sample thickness [31,32]. This geometry-induced delamination differs from the fiber configuration-induced delamination observed in Fig. 6. ...
3D printing of continuous fiber reinforced thermoplastic matrix composites has been increasingly used in manufacturing high-performance prototypes or even functional parts. It has allowed engineers and researchers to produce composites with custom design on their fiber configurations besides geometries. This work focuses on studying the printability of continuous fiber reinforced thermoplastic composites with different fiber configurations, including cross-ply, unidirectional, and complex helicoidal structures with different fiber angles, as well as evaluating their impact performance and failure mechanisms from impact. It was found that main failure mechanisms at the filament level included filament fracture, in-plane debonding and through-thickness debonding of continuous fiber composite filaments at the impact site. Interlaminar delamination occurred to some samples and both fiber configuration and sample thickness affected its occurrence. The impact testing results also showed that printed continuous glass fiber composite had better impact performance than printed continuous Kevlar fiber composite. The findings of this work can provide guidelines in both geometry and fiber configuration design to achieve different failure mechanisms for 3D printed continuous fiber composites under impact.
In this paper, a numerical program to calculate shear correction factors of complex plane sections in the case of deformation of simple bending beams with moderate dimensions is developed. Shear force influences the deflection calculation that becomes non-negligible. The elementary stiffness matrix of the finite element will be modified or become dependent on some shear correction factors of the section. It is then useful to find for each section its shear correction factors given their importance in practice. In the literature, exact analytical solutions only exist for some simple geometric shapes such as circular and rectangular sections, hence the interest in orienting our investigations towards numerical solutions for other complex sections used in aeronautics. The program has been validated by the numerical convergence results toward those obtained for circular and rectangular sections whose exact solutions are displayed. It should be noted that the relative error for a high discretization tends toward zero. Given their various applications in aeronautics as well as in industrial mechanics, the aerodynamic profiles are the subject of this numerical investigation.
