Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror...Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror plus 4J32 flexible support plus ZTC4 support back plate, the second K9 mirror plus 4J45 flexible support plus ZTC4 support back plate, and the third SiC mirror plus SiC rigid support back plate. A coupled thermo-mechanical analysis of the three primary mirror assemblies was made with finite element method. The results show that the SiC assembly is the best of all schemes in terms of their combination properties due to its elimination of the thermal expansion mismatch between the materials. The analytical results on the cryogenic property of the SiC primary mirror assembly show a higher surface finish of the SiC mirror even under the cryogenic condition.展开更多
According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror ...According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror assembly was designed. Finite element analysis combined with the parameter-optimized method was used during the design. Lightweight cell and rigid rib structure were used for the mirror assembly. The static, dynamic and thermal properties of the primary mirror assembly were analyzed. It is shown that after optimization, the lightweight ratio of the silicon carbide mirror is 52.5%, and the rigidity of the silicon carbide structure is high enough to support the required mirror. When temperature changes, the deformation of the mirror surface is in proportion to the temperature difference.展开更多
Purpose:In order to evaluate the mechanical feasibility of the domestic baffle made by wire electrode cutting for the mirror assembly of the Follow-up X-ray Telescope(FXT)onboard the Einstein Probe(EP)mission.Methods:...Purpose:In order to evaluate the mechanical feasibility of the domestic baffle made by wire electrode cutting for the mirror assembly of the Follow-up X-ray Telescope(FXT)onboard the Einstein Probe(EP)mission.Methods:Finite element analysis was performed to compare the structural differences between the domestic baffle made by wire electrode cutting and the eROSITA baffle made by bonding.The finite element models were verified by test data in advance to avoid significant deviations.Finally,the differences in dynamical performances between the FXT mirror assemblies with the two baffles were investigated through modal analysis and frequency response analysis using the pre-verified models.Results and conclusions:The results show that,from the perspective of the entire mirror assembly,their eigenfrequencies remain similar,except for the second lateral eigenfrequency,which shifts forward by approximately 24 Hz in the mirror assembly equipped with the domestic baffle.However,for the X-ray baffles themselves,the axial and lateral eigenfrequencies of the two baffles differ by approximately 49 Hz and 185 Hz,respectively.These eigenfrequencies are staggered,ensuring that over-response is avoided.In terms of response amplification,the domestic baffle,compared to the eROSITA baffle,exhibits inferior axial mechanical characteristics but superior lateral characteristics.In summary,from a mechanical perspective,the domestic baffle is feasible.展开更多
文摘Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror plus 4J32 flexible support plus ZTC4 support back plate, the second K9 mirror plus 4J45 flexible support plus ZTC4 support back plate, and the third SiC mirror plus SiC rigid support back plate. A coupled thermo-mechanical analysis of the three primary mirror assemblies was made with finite element method. The results show that the SiC assembly is the best of all schemes in terms of their combination properties due to its elimination of the thermal expansion mismatch between the materials. The analytical results on the cryogenic property of the SiC primary mirror assembly show a higher surface finish of the SiC mirror even under the cryogenic condition.
文摘According to the design requirement and on the basis of the principle that the thermal expansion coefficient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror assembly was designed. Finite element analysis combined with the parameter-optimized method was used during the design. Lightweight cell and rigid rib structure were used for the mirror assembly. The static, dynamic and thermal properties of the primary mirror assembly were analyzed. It is shown that after optimization, the lightweight ratio of the silicon carbide mirror is 52.5%, and the rigidity of the silicon carbide structure is high enough to support the required mirror. When temperature changes, the deformation of the mirror surface is in proportion to the temperature difference.
基金supported by the Einstein Probe(EP)Program which is funded by the"Strategic Priority Research Program"of the Chinese Academy of Sciences(Grant No.XDA15310103).
文摘Purpose:In order to evaluate the mechanical feasibility of the domestic baffle made by wire electrode cutting for the mirror assembly of the Follow-up X-ray Telescope(FXT)onboard the Einstein Probe(EP)mission.Methods:Finite element analysis was performed to compare the structural differences between the domestic baffle made by wire electrode cutting and the eROSITA baffle made by bonding.The finite element models were verified by test data in advance to avoid significant deviations.Finally,the differences in dynamical performances between the FXT mirror assemblies with the two baffles were investigated through modal analysis and frequency response analysis using the pre-verified models.Results and conclusions:The results show that,from the perspective of the entire mirror assembly,their eigenfrequencies remain similar,except for the second lateral eigenfrequency,which shifts forward by approximately 24 Hz in the mirror assembly equipped with the domestic baffle.However,for the X-ray baffles themselves,the axial and lateral eigenfrequencies of the two baffles differ by approximately 49 Hz and 185 Hz,respectively.These eigenfrequencies are staggered,ensuring that over-response is avoided.In terms of response amplification,the domestic baffle,compared to the eROSITA baffle,exhibits inferior axial mechanical characteristics but superior lateral characteristics.In summary,from a mechanical perspective,the domestic baffle is feasible.
