Getting Maximal Stress Value

You can get the top 1 using Selection Set.

Here is example.

set type 'node'; #element or node#
set t [clock click];
hwi OpenStack;
hwi GetSessionHandle sess$t;
sess$t GetProjectHandle proj$t;
proj$t GetPageHandle page$t [proj$t GetActivePage];
page$t GetWindowHandle wind$t [page$t GetActiveWindow];
wind$t GetClientHandle ****$t;
****$t GetModelHandle modl$t [****$t GetActiveModel];
modl$t GetSelectionSetHandle set1$t [modl$t AddSelectionSet $type];
set1$t Add 'contour top 1';
set1$t SetLabel '$type set top 1';
****$t Draw;
tk_messageBox -message 'Top1 $type ID = [set1$t GetList]';
hwi CloseStack;