Research On The Optimization Design Of Longitudinal-Transverse Stiffened Deep-Submerged Launch Tube

The launch of torpedo in deep sea is an important technology to improve the disguise abilityof submarine in combat, the pressure-balanced underwater torpedo launch system which hasbeen widely applied provides theoretical basis for the realization of this technology, and how tokeep the stability and reliability of structure under the condition of large depth is a majorproblem need to be investigated, what is more, there is a requirement of lightweight. From thatstandpoint, this paper proposes to introduce longitudinal-transverse stiffened launch tube, andexplore the structural optimization method to approach minimum mass under the condition oflarge depth.The main contents of this paper are as follow:1. Discuss the limit that the torpedo cannot be launch out of tube in case the tube axis hasbent severely in deep sea subject to the deformation of the pressure hull. Make a mathematicaldescription and analysis of the critical failure state of tube system for the first time, thecalculation results show that there is little probability of structure failure for the bending of tube.2. Stiffened cylindrical shell is a widely used structure form in engineering, there areseveral methods for the analysis of its strength and stability, based on theoretical analysis, thispaper proposes several analytic calculation methods for the design of stiffened tube according tothe design standards of steel pressure vessels and submarine structure, and makes a comparisonbetween the two kinds of method to explore whether they are suitable for the design ofdeep-submerged launch tube.3. Based on analytic calculation method, a mathematics model is proposed to optimize theweight of launch tube, in order to acquire the global optimal solution of the nonlinear discreteoptimization problem, author adopts genetic algorithm and obtains the desired results bydeveloping corresponding program in MATLAB, the application of this program can improve theefficiency of launch tube design, the optimization results show that the standard of submarinestructure is more suitable for the design of deep-submerged launch tube.4. For the reason that the local searching capacity of genetic algorithm is weak, this paperintegrates MATLAB into Isight and adopts combinatorial optimization strategy to complete theoptimization design of longitudinal-transverse stiffened launch tube, the results are improved,and show that the total stability of tube is the main constraint of optimization design, thisresearch can provide technical support for the actualization of multidisciplinary designoptimization platform based on Isight. 5. Based on the ANSYS parameter design language, this paper establishes a parametricmodel of stiffened tube and realizes the nonlinear buckling analysis, compared to analyticcalculation methods, the value of critical load from finite element analysis method is smaller, themethod can provide basis for the validation of structure stability and rationality, the research canalso provide technical foundation for integrating ANSYS into Isight.