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Formation Of Circular Optical Membranes Under Free-Form Yielding, Christopher Tuan, David White
Formation Of Circular Optical Membranes Under Free-Form Yielding, Christopher Tuan, David White
Christopher Y. Tuan
High‐quality optical reflector surfaces are attainable with the use of pressure‐formed membranes. The formation technique involves gradual application of fluid pressure on initially flat, simply supported circular membranes until a desirable center deflection is reached. After the fluid is removed, a uniform pressure is subsequently applied to offset the surface slope error. Empirical testing of membrane‐forming technique was conducted at two scales to define the critical process variables that controlled material yielding. Aluminum membranes with 54‐in. (1.4‐m) diameter were constructed for the smaller scale and with 144‐in. (3.7‐m) diameter for the larger scale. The experiments were carried out with the …
Uniform Pressure Formation Of Optical Membranes, Christopher Tuan, L. Murphy
Uniform Pressure Formation Of Optical Membranes, Christopher Tuan, L. Murphy
Christopher Y. Tuan
High‐quality optical reflector surfaces are attainable with the i use of pressure‐formed membranes. Those reflector surfaces offer the prospect of very light weight and low cost. The formation of those surfaces, using initially flat circular membranes with uniform pressure loading, is studied in this paper. Finite axisymmetric deformations, along with both linear and nonlinear material responses are considered. A wide range of focal‐length‐to‐diameter ratios are addressed, and the structural/optical response mechanisms that lead to optical distortions relative to ideal parabolic reflector shapes are also considered. Results show that elastic material response can often lead to a significantly larger deviation from …