Bistable　structures,　exemplified　by　the　Venus　flytrap　and　slap　bracelets,　can　transit　between　different　configurations　upon　certain　external　stimulation.　Here　we　study,　through　three-dimensional　finite　element　simulations,　the　bistable　behaviors　in　elastic　plates　in　the　absence　of　terminate　loads,　but　with　pre-strains　in　one　(or　both)　of　the　two　composite　layers.　Both　the　scenarios　with　and　without　a　given　geometric　mis-orientation　angle　are　investigated,　the　results　of　which　are　consistent　with　recent　theoretical　and　experimental　studies.　This　work　can　open　ample　venues　for　programmable　designs　of　plant/shell　structures　with　large　deformations,　with　applications　in　designing　bio-inspired　robotics　for　biomedical　research　and　morphing/deployable　structures　in　aerospace　engineering.