航天返回与遥感
航天返迴與遙感
항천반회여요감
SPACECRAFT RECOVERY & REMOTE SENSING
2014年
5期
19-24
,共6页
卫剑征%马瑞强%张雯婷%谭惠丰%黄伟
衛劍徵%馬瑞彊%張雯婷%譚惠豐%黃偉
위검정%마서강%장문정%담혜봉%황위
气动阻力锥%充气结构%力学特性%再入
氣動阻力錐%充氣結構%力學特性%再入
기동조력추%충기결구%역학특성%재입
aeroshell%inflatable structure%mechanical properties%reentry
为了研究双层充气式气动阻力锥二级展开对其力学性能的影响,文章首先基于有限单元方法,利用Newton-Raphson非线性迭代计算方法分析并比较了二级展开前后的气动阻力锥结构充压变形特征,并获取二者最大应力随充气压力的变化规律;然后引入气动阻力锥结构预应力刚化效应,计算预应力下气动阻力锥结构的振动模态;最后,研究二级阻力面展开瞬时对气动阻力锥最大压力、最大温度以及气动阻力等特性的影响。结果表明:气动阻力锥二级展开,在某种程度上会引起结构强度的下降;也导致结构第三阶模态频率降低,使结构更容易受到外界激励而产生颤振,甚至导致结构破坏;但气动阻力锥的二次展开可以使得结构气动阻力增加两倍之多,可保证气动阻力锥安全抵达地面。因此,合理选择二级展开对应的飞行速度可以增加结构的安全性。
為瞭研究雙層充氣式氣動阻力錐二級展開對其力學性能的影響,文章首先基于有限單元方法,利用Newton-Raphson非線性迭代計算方法分析併比較瞭二級展開前後的氣動阻力錐結構充壓變形特徵,併穫取二者最大應力隨充氣壓力的變化規律;然後引入氣動阻力錐結構預應力剛化效應,計算預應力下氣動阻力錐結構的振動模態;最後,研究二級阻力麵展開瞬時對氣動阻力錐最大壓力、最大溫度以及氣動阻力等特性的影響。結果錶明:氣動阻力錐二級展開,在某種程度上會引起結構彊度的下降;也導緻結構第三階模態頻率降低,使結構更容易受到外界激勵而產生顫振,甚至導緻結構破壞;但氣動阻力錐的二次展開可以使得結構氣動阻力增加兩倍之多,可保證氣動阻力錐安全牴達地麵。因此,閤理選擇二級展開對應的飛行速度可以增加結構的安全性。
위료연구쌍층충기식기동조력추이급전개대기역학성능적영향,문장수선기우유한단원방법,이용Newton-Raphson비선성질대계산방법분석병비교료이급전개전후적기동조력추결구충압변형특정,병획취이자최대응력수충기압력적변화규률;연후인입기동조력추결구예응력강화효응,계산예응력하기동조력추결구적진동모태;최후,연구이급조력면전개순시대기동조력추최대압력、최대온도이급기동조력등특성적영향。결과표명:기동조력추이급전개,재모충정도상회인기결구강도적하강;야도치결구제삼계모태빈솔강저,사결구경용역수도외계격려이산생전진,심지도치결구파배;단기동조력추적이차전개가이사득결구기동조력증가량배지다,가보증기동조력추안전저체지면。인차,합리선택이급전개대응적비행속도가이증가결구적안전성。
In order to study the effect of the secondary deployment of double-layer inflatable aeroshell structure on its mechanical characteristics, first, the pressurized deformation of the structure before and after secondary inflation is analyzed and compared by using the Newton-Raphson iteration method in this paper based on finite element method , and the change of the maximum stresse with the inflation pressure is obtained. Then, based on the pre-stressed stiffening effect of the two inflatable aeroshell structures on the inflation pres-sure, the vibration modes are calculated. Finally, the influence of the secondary inflation on the maximum pressure, maximum temperature and the aerodynamic drag of the flow field around the structure are researched. The results show that both the structural strength and the third modal frequencies of this structure decrease when the structure achieves the secondary inflation, which implies the structures are easier to flutter due to ex-ternal excitation. However, the aerodynamic drag of the inflatable aeroshell structure has a more than three-fold increase due to the secondary inflation, which ensures the structure’s safe landing on the ground. Therefore, if a reasonable flight speed for the secondary unfolding is chosen, and the security of the structure will be increased to some extent.