一块在工作台上感觉很坚硬的板材，当其超出安装支架范围时，可能会出现明显的弯曲。未受支撑的长度、载荷位置以及支架处的约束条件都起着重要作用。仅规定厚度并不能解决该问题的大部分。.
Measure from the support, not the outside edge
The working span begins where the panel is actually restrained. A bracket may overlap a large area while contacting only a narrow strip. A soft pad, loose fastener or flexible supporting frame can change that restraint again. A sketch showing the contact region and the load location is more useful than a thickness request made in isolation.
Why a longer overhang is a different design
For an ideal, uniform cantilever beam with a point load at its free end, the elementary bending model makes tip deflection proportional to the cube of length when the other terms remain fixed. That is a useful explanation of why small changes in overhang deserve attention. It is not a direct sizing rule for every composite panel: laminate direction, panel width, cutouts, joint flexibility and the actual loading can require a more suitable analysis.
Put the allowable movement in practical terms
State where movement matters. A tray carrying a sensor may be limited by alignment with another component, while a cover may only need to stay clear of a moving mechanism. These are different requirements even if the applied force is similar. Give the relevant load case and a measurable displacement limit at the point that affects operation.
What to take to a supplier review
Bring the mounting layout, support construction and proposed load locations together with the panel outline. If a first sample will be checked, agree the loading arrangement and measurement point before interpreting the result. A hand-held bend comparison can be a quick discussion aid, but it cannot replace a recorded acceptance condition for a repeat order.
Technical background: MIT OpenCourseWare: cantilever beam example.