Influence Of Structures And Composite Materials’ Constituents On The Stiffness Of The70Meters Ship

With the development of the material science, the materials of ships change tonew materials gradually. Composite materials, especially the glass fiber reinforcedplastics(GFRP), have become a mainstream of the ships’ materials. Due to the smallelastic modulus of the glass fiber reinforced plastics, the stiffness can not meet therequirements. This will impede the development of the large ships and cause allkinds of security problems. Therefore, it is necessary to study the methods that canimprove the stiffness of the composite materials ships.Under the premise of the same surfaces, this paper stud ies the methods that canimprove the stiffness of ships in two ways, hull structures and composite materials’constituents.Firstly, the hull structures’ impact on stiffness of ships should be considered.Hull structures have a direct impact on the performance of ships. In this paper, fivekinds of hull structures, namely: transverse frame, longitudina l frame,combined-frame, hard shell structure, sandwich structure, are designed. Taking intoaccount the same working conditions, this paper analyses the above-mentioned hullstructures and selects the optimal hull structure.Secondly, the impact of composite materials’ constituents on ships’ stiffnessalso should be considered. Because the composite materials can be designed, thispaper analyses the hull structure with the composite materials designed andcompares with the equal mass steel ship to study the impact of different materials onthe static stiffness and dynamic stiffness.Thirdly, taking into account the special working condition of ships, this paperstudies the theories of blast load and numerical calculation about ships withunderwater explosion is executed in MSC.Dytran, a transient dynamics software.Thereby the analyses verify that the methods improving ship stiffness are effective.Ultimately, by the study of hull structures and composite materials’ constituents,it is raised the methods improving stiffness of the composite materials ships. For thedevelopment of large ships and the optimization of the overall performance, thispaper provides the support of theories and numerical analyses.