Thermal stress in meteoroids by aerodynamic heating is calculated for the ideal case of an isotropic,homogeneous,elastic sphere being heated at the surface with a constant heat transfer coefficient.Given enough time,t...Thermal stress in meteoroids by aerodynamic heating is calculated for the ideal case of an isotropic,homogeneous,elastic sphere being heated at the surface with a constant heat transfer coefficient.Given enough time,the tensile stress in the interior of the meteoroid can be as high as 10 kb.This stress value is greater than estimated tensile strengths of meteoroids and the aerodynamic compression they encounter.Significant thermal stress(1 kb) can develop quickly(within a few tens of seconds) in a small(radius<10 cm) stony meteoroid and a somewhat large(radius<1 m)metallic meteoroid,and thus may cause tensile fracture to initiate in the meteotoid’s interior.Fracture by thermal stress may have contributed to such observations as the existence of dust particles in upper atmosphere,the breakup of meteoroids at relatively low altitudes,the angular shape of meteorites and their wide scattering in a strewn field,and the explosive features of impact craters.In large meteoroids that require longer heating for thermal stress to fully develop,its effect is probably insignificant.The calculated stress values may be upper limits for real meteoroids which suffer melting and ablation at the surface.展开更多
Last April, while attending the Western Pacific Meeting organized by the American Geophysical Union in Taiwan, I received a call from Prof. Xue Hongjiao, inviting me to join the editorial committee of the journal of G...Last April, while attending the Western Pacific Meeting organized by the American Geophysical Union in Taiwan, I received a call from Prof. Xue Hongjiao, inviting me to join the editorial committee of the journal of Geodesy and Geodynamics in charge of English editing.展开更多
文摘Thermal stress in meteoroids by aerodynamic heating is calculated for the ideal case of an isotropic,homogeneous,elastic sphere being heated at the surface with a constant heat transfer coefficient.Given enough time,the tensile stress in the interior of the meteoroid can be as high as 10 kb.This stress value is greater than estimated tensile strengths of meteoroids and the aerodynamic compression they encounter.Significant thermal stress(1 kb) can develop quickly(within a few tens of seconds) in a small(radius<10 cm) stony meteoroid and a somewhat large(radius<1 m)metallic meteoroid,and thus may cause tensile fracture to initiate in the meteotoid’s interior.Fracture by thermal stress may have contributed to such observations as the existence of dust particles in upper atmosphere,the breakup of meteoroids at relatively low altitudes,the angular shape of meteorites and their wide scattering in a strewn field,and the explosive features of impact craters.In large meteoroids that require longer heating for thermal stress to fully develop,its effect is probably insignificant.The calculated stress values may be upper limits for real meteoroids which suffer melting and ablation at the surface.
文摘Last April, while attending the Western Pacific Meeting organized by the American Geophysical Union in Taiwan, I received a call from Prof. Xue Hongjiao, inviting me to join the editorial committee of the journal of Geodesy and Geodynamics in charge of English editing.
