Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

No abstract

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.The joined-wing airplane proposed by Wolkovich in 1986 is defined as an airplane that incorporates tandem wings arranged to form diamond shapes in both top and front views. The joined-wing can lead to increased aerodynamic performances as well as reduction of the structural weight. However, the joined-wing has high geometric nonlinearity under the gust load. The gust load acts as a dynamic load. In previous researches, linear dynamic response optimization and nonlinear static responses optimization are performed. In this research, nonlinear dynamic response optimization of a joined-wing is carried out by using ?equivalent static loads,? a concept expanded and newly proposed for nonlinear dynamic response optimization. Equivalent static loads are the load sets which generate the same response field in linear static analysis as that from nonlinear dynamic analysis by repeated use of linear response optimization. For the verification of efficiency of the proposed method, a simple nonlinear dynamic response optimization problem is introduced. The problem is solved by using both the equivalent static loads method and the conventional method with sensitivity analysis using the finite difference method. The procedure for nonlinear dynamic response optimization of a joined-wing using equivalent static loads is explained and the optimum results are discussed 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report (SAR) 18. NUMBER OF PAGES 48 19a. NAME OF RESPONSIBLE PERSON a. REPORTunclassified b. ABSTRACT unclassified c. THIS PAGE unclassified 2 AbstractThe joined-wing configuration that was published by Wolkovich in 1986 has been studied by many researchers. The joined-wing airplane is defined as an airplane that incorporates tandem wings arranged to form diamond shapes in both top and front views. The joined-wing can lead to increased aerodynamic performances as well as reduction of the structural weight. However, the joinedwing has high geometric nonlinearity under the gust load. The gust load acts as a dynamic load. Therefore, nonlinear dynamic (transient) behavior of the joinedwing should be considered in structural optimization. In previous researches, linear dynamic respon...

No abstract