By using a fixed point theorem of mixed monotone operators in cone, this paper studied a fourth-order nonlinear singular boundary value problem, namely a class of elastic beam equation.

This paper discusses the existence of multiple positive solutions of a class of nonlinear singular boundary value problems by means of the fixed point index Theorem on cones.

By using fixed point index theory in a cone, we study the existence of positive solutions of boundary value problems for systems of nonlinear second order singular differential equations.