The present application relates to
large aperture optical
machine structure
engineering analysis technical field, especially to a kind of gravity unloading point
layout method of large space mirror, comprising the following steps: S1: the finite
element analysis model of space mirror is established, and the discrete node
surface shape data and unloadable point coordinate data are exported.S2:
surface shape fitting is carried out, and
surface shape accuracy is calculated.S3: its surface shape residual elevation diagram is drawn, and high residual point is identified.S4: the unloadable point coordinate of space mirror is obtained.S5: space mirror is supported using unloadable point, and its degree of freedom is constrained;Finite
element analysis model is updated, and step S2 is repeated, and surface shape accuracy is calculated.S6: whether surface shape accuracy meets the requirements is judged, if not, then repeat step S3 to step S5;Until meet the requirements.The present application has the advantages that, through the gravity unloading point
layout of space mirror, gravity unloading point can be more accurately fixed in flexible support mode or the like during
processing, and the influence of gravity on surface shape accuracy is reduced.