Three-dimensional stress analysis of orthotropic curved tubes-part 2: Laminate solution

Review of elasto-static models for three-dimensional analysis of thick-walled anisotropic tubes

“…An increase of fictious layers, by additionally dividing the physical layers in the analysis, showed an approximation of the stresses in thickness direction in comparison to a finite element (FE) calculation. A good agreement was also found to experimental studies 45 regarding three-point bending tests on pipes. Advantages of using the LWT for the cylindrical, orthotropic tube are simpler input values compared to FE calculations and a more accurate representation of the stresses and deformations in thickness direction compared to other tube models.…”

“…Only one of these methods is based on an anisotropic, three-dimensional tube model by Jolicoeur and Cardou. 46 A more detailed comparison of bending tests on tubes and analytical formulations by Jolicoeur and Cardou 46 was carried out by Derisi et al 74 The described models and papers by Sarvestani 45,[53][54][55][56][57] included validations with finite element method and experimental studies. Potential for future research work thence lies in the comparison and validation of these models as well as the extension to more complex load cases, such as coupled loads, and the consideration of singularities or inhomogeneities.…”

“…Indication of the layering with reference plane on the inner radius. 45 The equation for the bending moment can also be expressed by abbreviations of the coefficients of the unknowns according to the procedure for the displacements and stresses. This allows a conversion of the coefficents and boundary conditions into matrix notation and thus a linear system of equations for the three unknowns can be set up.…”

“…However, the models of the state-space approach, which are presented in section State-Space Approaches, usually use a displacement approach in combination with stresses. In addition to a few short descriptions of models with axisymmetric loads, this section presents the displacement-based approximity solutions according to Sarvestani et al 45,[53][54][55][56][57] for tubes under different bending loads. Displacement-based approaches provide a compatible displacement field for the continuum derived from the fundamental equations, which must be solved to obtain strains and stresses.…”

Effects of lay-up sequence in thick composite tubes for helicopter landing gears

“…Even though they have done experimental works, the analytical method does not exist to analyze thick composite tubes. Recently, the analytical method was developed by the authors 21,22 to investigate the curved part of helicopter landing gears. Here, the straight part is considered.…”