The submarine experiences longitudinal vibration in the propulsion shafting system throughout most of run. A transfer matrix model system, which dynamic characteristics oil film within thrust bearing are considered, is established to describe behavior. Using hydrodynamic lubrication theory and small perturbation method, axial stiffness damping deduced great detail, followed by numerical estimation foundation with finite element method. Based upon these values parameters, Campbell diagram...

The analysis of the influence hull deformation on shaft alignment is predominately conducted using finite element method (FEM), which time-consuming, labor-intensive, and challenging to use for iterative design optimization. In this paper, separated into two parts—global local deformation, simplified a single-span beam model grillage model, respectively—then solved matrix displacement (MDM). Compared FEM, proposed has small calculation error, proving its correctness, while time greatly...

Line heating is used in forming the complex curve plates of ships, and this process becoming integrated into automated tools. Induction equipment has become commonly automatic line heating. When applying equipment, it necessary to calculate relationship between parameters temperature field. Numerical methods are primarily accomplish calculations for induction This computation requires repeated iterations obtain a stable heat generation rate. Once rate changes significantly, recalculation...

Propeller-induced longitudinal vibration resonance in marine propulsion shafting systems causes great harm to the hull structure and is primary source of shipboard noise. Integrating a friction damper with designed parameters into thrust bearings can prevent these issues. To investigate performance damper-integrated bearing transmission control, an experimental theoretical study carried out laboratory-assembled test rig, which consists components similar existing system. We developed...

The longitudinal vibration of the propulsion shaft system is a challenging issue for marine noise management. We conducted various static and dynamic tests on our built test rig shafting system, presenting results in this paper. By combining experimental data particle swarm optimization algorithm, we identified structural parameters that are difficult to obtain. With these establish completed theoretical model containing branches, analyze how why thrust affects vibration, give quantitative...

Integrated heating and mechanical rolling forming (IHMRF) has recently been introduced for manufacturing complex curvature hull plates. It fabricates the target curved plate by sequential loading along multipath. Accurate efficient prediction of deformation is basis developing process planning ensuring quality forming. The inherent-strain method ideal this purpose, but its accuracy needs to be improved. This paper proposes a multipath process-based (MPISM), which considers effect on...

Abstract As a component of modern weaponry, the structural design and damage effects multifunctional warheads are directly linked to their combat performance. Targeting various urban objectives, we have proposed designed warhead structure that integrates multiple destructive elements, including directional divergent fragments, jets, linear EFPs, along with corresponding attack modes. Through numerical simulation analysis, evaluated different elements within this on equivalent target plates,...

This paper addresses a study on the resistance of clamped rectangular plate quasi-statically punched at mid-span by rigid indenter with knife and flat edge shape, through simplified analytical method. A new membrane stretching pattern is proposed resistancepenetration response obtained. To validate this method, series quasi-static tests specimens three lengthwidth ratios indenters six different scantlings are conducted. The well-matching resistance–penetration curves from calculations those...

Line heating is an essential process in the formation of ship hull plates with a complex curvature. Electromagnetic induction widely used line process. In electromagnetic heating, shape coil and air gap between inductor workpiece could influence heat source distribution. Moreover, process, change curvature plate will cause inductor. Magnetic thermal coupling calculation effective method for simulating heating. This paper finite element to calculate distribution sources different initial...

The unclear change laws of bearing offset and rotation, both which influence the condition shaft alignment during hull deformation, make it difficult to optimize shafting design. In this paper, an integrated hull-bearing-shaft model is designed built for a cantilever beam loading test. Displacement sensors are utilized determine in displacement hull, bearings, shaft. pressure distribution at bow stern ends measured using new type thin-film sensor. test results show that rotation angle varied...

The pressure distribution of a misaligned elastomeric journal bearing is crucial for analyzing the uneven excessive wearing propulsion shaft bearing. However, analysis usually mainly based on finite element method (FEM), which lacks convenient and effective calculation method. This paper uses influence coefficient factors (ICs) to analyze contact First, elastic displacement cylindrical shell subjected single point concentrated force derived used attain new factors. Then, geometric boundary...

The propulsion shafting is one typically continuous, elastic and stepped body. To design an active controller for by applying the modern control theory, accurate reduced-order model with lumped parameters required. This research concentrated on modelling method longitudinal vibration of a direct transfer marine shafting. modes were determined one-dimension wave approach based its continuous in advance. Taking into account unobservability uncontrollability mode nodes, nodes neglected low...

The main hull of a ship is made up large number plates with complex curvatures. Line heating one the approaches used in forming plate. Because line based on manual using handheld oxyacetylene gun, typical width extremely narrow. With development computer control technology, newly developed automated plate equipment available and its heat source typically an electromagnetic induction coil. temperature field coil size are correlated. However, investigations into scarce. In this study, effect...

Abstract. Local line rolling forming is a common approach for the complex curvature plate of ships. However, processing mode based on artificial experience still applied at present, because it difficult to integrally determine relational data shape, path, and process parameters used drive automation equipment. Numerical simulation currently major generating such data. Therefore, highly precise effective numerical computation method becomes crucial in development automated local system...

Finite element simulation of welding process has been wildly employed in engineering where deformation and residual stress are considered. One big problem during is the severe demands capacity hard disk computation time, especially for large structures with long weld length or multi-pass welding. To minimize number unknowns finite model, a rezoning technique developed to simulate process. The local nonlinear zone around current pass modeled dense mesh, while region other passes nearby...

Integrated heat and roll forming (IHMRF) is a process that uses thermal mechanical loads to produce localized plastic strains in plates form complex curvature hull plates. The magnitude of the resulting strain depends mainly on following parameters: machining parameters (power source, speed depth rollers), thickness plate, thermo-physical properties plate. Finding correspondence between key selecting appropriate for forming. A data-driven approach ideal this purpose. However, due...

Inherent strain method has been widely used as a forecasting and computing for welding deformation of large complicated structures further applied to the research line heating forming. Mechanical forming is common ship‐hull plate method, which prediction still depends mainly on elastoplastic finite element method. This paper researched application inherent rolling forming, mechanical then compared results proving applicability providing fast, accurate distortion in formation automation equipment.

The forming process of curved ship plate suffers from a low degree automation, mainly due to the lack an effective processing-scheme design method. In this paper, based on proposed concept “basic amount plasticity”, which can connect plastic strain induced by line heating and deformation form target shape, database is firstly established describe provided coil with specific processing parameters, considering effect boundary adjacent lines. Secondly, finite element method developed presented...