TY - GEN
T1 - Micromechanical analysis of composite truss-core sandwich panels for integral thermal protection systems
AU - Martinez, Oscar
AU - Bapanapalli, Satish
AU - Sankar, Bhavani
AU - Haftka, Raphael
AU - Blosser, Max
PY - 2006
Y1 - 2006
N2 - A composite truss-core sandwich panel is investigated as a potential candidate for an Integral Thermal Protection System (ITPS). This multi-functional ITPS concept will protect the space vehicle from extreme reentry temperatures and will possess load carrying capabilities. The truss core is composed of two thin flat sheets that are separated by two inclined plates. Advantages of this new ITPS concept are discussed. The sandwich structure is idealized as an equivalent orthotropic thick plate continuum. The extensional stiffness matrix [A], coupling stiffness matrix [B], bending stiffness [D] and the transverse shear stiffness terms A44 and A55 are calculated through a strain energy and axes transformation approach. Using the Shear Deformable Plate Theory (SDPT) a closed form solution of the plate response was derived. The behavior of the stiffness and maximum plate deflection due to changing the web angle inclination is discussed. The calculated results, which require significantly less computational effort and time, agree well with the 3D finite-element analysis. The study indicates that panels with rectangular webs resulted in a weak extensional, bendiag, and A55 stiffness and that maximum plate deflection was greatest for 48° web angle configuration. The micromechanical analysis procedures developed in this study is to determine the unit cell stresses for each component (isotropic or composite) of the truss (face or web) that is caused by a uniform pressure load.
AB - A composite truss-core sandwich panel is investigated as a potential candidate for an Integral Thermal Protection System (ITPS). This multi-functional ITPS concept will protect the space vehicle from extreme reentry temperatures and will possess load carrying capabilities. The truss core is composed of two thin flat sheets that are separated by two inclined plates. Advantages of this new ITPS concept are discussed. The sandwich structure is idealized as an equivalent orthotropic thick plate continuum. The extensional stiffness matrix [A], coupling stiffness matrix [B], bending stiffness [D] and the transverse shear stiffness terms A44 and A55 are calculated through a strain energy and axes transformation approach. Using the Shear Deformable Plate Theory (SDPT) a closed form solution of the plate response was derived. The behavior of the stiffness and maximum plate deflection due to changing the web angle inclination is discussed. The calculated results, which require significantly less computational effort and time, agree well with the 3D finite-element analysis. The study indicates that panels with rectangular webs resulted in a weak extensional, bendiag, and A55 stiffness and that maximum plate deflection was greatest for 48° web angle configuration. The micromechanical analysis procedures developed in this study is to determine the unit cell stresses for each component (isotropic or composite) of the truss (face or web) that is caused by a uniform pressure load.
UR - http://www.scopus.com/inward/record.url?scp=34147189630&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:34147189630
SN - 1563478080
SN - 9781563478086
T3 - Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
SP - 3453
EP - 3471
BT - Collection of Technical Papers - 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
T2 - 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
Y2 - 1 May 2006 through 4 May 2006
ER -