کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1769210 1020261 2006 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A constitutive equation for stratospheric balloon materials
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم فضا و نجوم
پیش نمایش صفحه اول مقاله
A constitutive equation for stratospheric balloon materials
چکیده انگلیسی

The selection of a suitable material for use as a reliable stratospheric balloon gas barrier and structural component is based on a variety of properties. Due to a more desirable combination of properties, the low density polyethylene that has been used for the last half century has been replaced during the last decade by linear low density polyethylene (LLDPE). This paper describes the effort to characterize the time dependent properties of a 38 micron coextrusion of LLDPE. The nonlinear viscoelastic constitutive equation presented may be used to accurately describe the creep and/or relaxation of this film when subjected to a biaxial state of stress, such as might be required for an extended balloon flight. Recent laboratory data have been used to modify an existing model of LLDPE to account for differences caused by the coextrusion process. The new model will facilitate structural design optimization and reliability assessment, and may be further utilized as a predictive tool to benefit in-flight operations. Current structural analysis techniques based on linear elastic properties have predicted stresses in excess of those which would actually exist.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Advances in Space Research - Volume 37, Issue 11, 2006, Pages 2087–2091
نویسندگان
, ,