A truss-core sandwich panel is consisted of two facing plates and a truss-core connecting the top and the bottom
surface sheets together. To analyze the bending behavior of a truss-core sandwich panel under static load in its weak
direction, the equation for predicting the deflection of a truss-core sandwich panel is deduced through assumptions and
theoretical analysis. To verify the accuracy of the presented equation, a comparison between predicted theoretical results
and finite element results has been conducted. A parametric study has also been carried out to determine the validity range
of the proposed equation. Through the comparison between the parametric results and finite element results, the error
variation has been investigated. It is found that the values obtained from the presented equation agree quite well with the
results derived from the finite element analysis in a geometrical validity range of truss-core sandwich panels.