The Application of ANSYS Multipoint Constraint on the Combination Modeling of SOLID-SHELL

2012 ◽  
Vol 588-589 ◽  
pp. 226-229
Author(s):  
Bao Qin Zhang ◽  
Jian Xia He ◽  
Yun Fang Qiao
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Shell Element ◽  
Engineering Practice ◽  
Solid Shell ◽  
Element Modeling ◽  
Constraint Equations ◽  
Solid Element ◽  
Different Types

The problem of the modeling connection of different units is encountered in engineering practice. Its reasonable proposals are that the modeling is discrete into the respective discrete three-dimensional solid elements for calculation. But different types of units’ degrees of freedom are not discontinuity，it will lead to significant deviation of calculated results and the actual. In the paper, the methods and characteristics of SOLID-SHELL unit with the application of ANSYS constraint equations method and the MPC law are discussed, and compared the shell - solid element with the whole solid element modeling combined the results, it draw a conclusion that MPC law is advantage in modeling of three-dimensional solid element and shell element.

Solid Shell Element and its Application in Roll Forming Simulation

2007 ◽  
Vol 340-341 ◽  
pp. 347-352 ◽  
Author(s):  
Da Yong Li ◽  
Ying Bing Luo ◽  
Ying Hong Peng
Keyword(s):  
Degrees Of Freedom ◽  
Shell Element ◽  
Element Model ◽  
Roll Forming ◽  
Good Prospect ◽  
Solid Shell ◽  
Forming Process ◽  
Forming Simulation ◽  
Assumed Natural Strain ◽  
Roll Forming Process

Solid shell element models which possess only translational degrees of freedom and are applicable to thin structure analyses has drawn much attention in recent years and presented good prospect in sheet metal forming. In this study, a solid shell element model is introduced into the dynamic explicit elastic-plastic finite element method. The plane stress constitutive relation is assumed to relieve the thickness locking and the selected reduced integration method is used to overcome volumetric locking. The assumed natural strain method is adopted to resolve shear locking and trapezoidal locking problem. Two benchmark examples and a stage of roll forming process are calculated, and the calculating results are compared with those by solid element model, which demonstrates the effectiveness of the element.

An Efficient Finite Element Modeling of Composite Stiffened Shells

2014 ◽  
Vol 553 ◽  
pp. 673-678
Author(s):  
Hamid Sheikh ◽  
Liang Huang
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Degrees Of Freedom ◽  
Torsional Rigidity ◽  
Shell Element ◽  
Beam Element ◽  
Shell Elements ◽  
Element Modeling ◽  
Stiffened Shells ◽  
Element Technique

This paper presents an efficient finite element modeling technique for stiffened composite shells having different stiffening arrangements. The laminated shell skin is modeled with a triangular degenerated curved shell element having 3 corner nodes and 3 mid-side nodes. An efficient curved beam element compatible with the shell element is developed for the modeling of stiffeners which may have different lamination schemes. The formulation of the 3 nod degenerated beam element may be considered as one of the major contributions. The deformation of the beam element is completely defined in terms of the degrees of freedom of shell elements and it does not require any additional degrees of freedom. As the usual formulation of degenerated beam elements overestimates their torsional rigidity, a torsion correction factor is introduced for different lamination schemes. Numerical examples are solved by the proposed finite element technique to assess its performance.

Three-dimensional stress analysis of tubular joint using rezone technique

1986 ◽  
Vol 13 (3) ◽  
pp. 382-385
Author(s):  
G. S. Bhuyan ◽  
M. Arockiasamy ◽  
K. Munaswamy
Keyword(s):  
Stress Analysis ◽  
Transition Zone ◽  
Degrees Of Freedom ◽  
Hot Spot ◽  
Three Dimensional ◽  
Axial Loading ◽  
Boundary Displacement ◽  
Solid Element ◽  
Weld Toe ◽  
Tubular Joint

This note presents three-dimensional stress analysis results of a welded tubular T-joint under axial loading, using rezone technique. The rezone technique is used to reduce computer storage requirements, as well as solution costs, that result from the large number of degrees-of-freedom associated with three-dimensional analysis of the entire joint using solid elements. The hot-spot region around the weld toe and the weld reinforcement are modelled using three-dimensional incompatible 8-node brick and 6-node prism elements. The boundary nodal displacements for the rezoned model are obtained from plate analysis of the entire joint. The boundary values, at the plate-to-solid element transition zone, are distributed between two solid element nodes maintaining boundary displacement compatibility. The stresses at the critical lines, obtained from the rezoned analysis, are compared with those of the entire three-dimensional and plate model analyses. Key words: tubular joint, rezoned model, transition zone, boundary displacement compatibility, incompatible elements.

Modal Analysis Method for Blisks Based on Three-Dimensional Blade and Two-Dimensional Axisymmetric Disk Finite Element Model

2016 ◽  
Vol 139 (5) ◽  
Author(s):  
Wangbai Pan ◽  
Guoan Tang ◽  
Meiyan Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Degrees Of Freedom ◽  
Mechanical Energy ◽  
Three Dimensional ◽  
Element Model ◽  
Computational Time ◽  
Engineering Practice ◽  
Analysis Method

In this paper, a novel and efficient modal analysis method is raised to work on blisk structures based on mixed-dimension finite element model (MDFEM). The blade and the disk are modeled separately. The blade model is figured by 3D solid elements considering its complex configuration and its degrees-of-freedom (DOFs) are condensed by dynamic substructural method. Meanwhile, the disk is structured by 2D axisymmetric element developed specially in this paper. The DOFs of entire blisk are tremendously reduced by this modeling approach. The key idea of this method is derivation of displacement compatibility to different dimensional models. Mechanical energy equivalence and summation further contribute to the model synthesis and modal analysis of blade and disk. This method has been successfully applied on the modal analysis of blisk structures in turbine, which reveals its effectiveness and proves that this method reduces the computational time expenses while maintaining the precision performances of full 3D model. Though there is limitation that structure should have proper coverage of blades, this method is still feasible for most blisks in engineering practice.

scholarly journals A new prismatic solid-shell element ‘SHB6’: Assumed-strain formulation and evaluation on benchmark problems

2009 ◽  
Vol 31 (3-4) ◽  
Author(s):  
Vuong Dieu Trinh ◽  
Farid Abed-Meraim ◽  
Alain Combescure
Keyword(s):  
Degrees Of Freedom ◽  
Shell Element ◽  
Careful Analysis ◽  
Benchmark Problems ◽  
Integration Scheme ◽  
Solid Shell ◽  
Structural Problems ◽  
Assumed Strain ◽  
Assumed Strain Method ◽  
Strain Method

In this paper, the formulation of a new six-node solid–shell element denoted (SHB6) is proposed. This prismatic element is based on a purely three-dimensional approach, and hence has displacements as the only degrees of freedom. A reduced integration scheme is adopted consisting of one-point in-plane quadrature and an arbitrary number of integration points, with a minimum number of two, distributed along the ‘thickness’ direction. Moreover, in order to enhance its performance and to greatly reduce most locking effects, specific projections are introduced based on the assumed-strain method. The resulting derivation can then be used to model thin structural problems, while taking into account the various through-thickness phenomena. A careful analysis of potential stiffness matrix rank deficiencies reveals that no hourglass modes need to be controlled. However, without assumed-strain method, the element exhibits some shear and thickness-type locking, which is common in linear triangular elements associated with constant strain states. After the formulation of the element is detailed, its performance is assessed through a set of representative benchmark problems illustrating its capabilities in various situations. More specifically, this prismatic solid–shell element proves to be an essential complement to the SHB8PS hexahedral element in meshing arbitrarily complex geometries.

Nonlinear Analysis of Twisted Wind Turbine Blade

2016 ◽  
Vol 34 (3) ◽  
pp. 269-278 ◽  
Author(s):  
M. Yangui ◽  
S. Bouaziz ◽  
M. Taktak ◽  
M. Haddar ◽  
A. El-Sabbagh
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Degrees Of Freedom ◽  
Rotation Speed ◽  
Three Dimensional ◽  
Nonlinear Problems ◽  
Shell Element ◽  
Element Model ◽  
Angular Rotation ◽  
Triangular Shell Element

AbstractModal analysis is developed in this paper in order to study the dynamic characteristics of rotating segmented blades assembled with spar. Accordingly, a three dimensional finite element model was built using the three node triangular shell element DKT18, which has six degrees of freedom, to model the blade and the spar structures. This study covers the effect of rotation speed and geometrically nonlinear problems on the vibration characteristics of rotating blade with various pretwist angles. Likewise, the effect of the spar in the blade is taken into consideration. The equation of motion for the finite element model is derived by using Hamilton's principle, while the resulting nonlinear equilibrium equation is solved by applying the Newmark method combined with the Newton Raphson schema. Results show that the natural frequencies increase by taking account of the spar, they are also proportional to the angular rotation speed and influenced by geometric nonlinearity and pretwist angle.

Mobility and Geometrical Analysis of a Two Actuated Spoke Wheel Robot Modeled as a Mechanism With Variable Topology

2008 ◽  
Author(s):  
Ya Wang ◽  
Ping Ren ◽  
Dennis Hong
Keyword(s):  
Degrees Of Freedom ◽  
Contact Point ◽  
Future Research ◽  
Coordinate Systems ◽  
Line Geometry ◽  
Geometrical Analysis ◽  
Constraint Equations ◽  
Contact Points ◽  
Different Types ◽  
Variable Topology

In this paper, the mobility and geometrical analysis of a novel mobile robot that utilizes two actuated spoke wheels is presented. Intelligent Mobility Platform with Active Spoke System (IMPASS) is a wheel-leg hybrid robot that can walk in unstructured environments by stretching in or out three independently actuated spokes of each wheel. First, the unique locomotion scheme of IMPASS is introduced and the definitions of the coordinate systems are developed to describe the kinematic configurations. Since this robot is capable of utilizing its metamorphic configurations to implement different types of motion, its topology structures are classified into different groups based on the cases of ground contact points. For each contact point case, the mobility analysis is performed using the conventional Gru¨bler and Kutzbach criterion. However, as for the cases in which the structure is overconstrained, the Modified Gru¨bler and Kutzbach criterion based on reciprocal screws are implemented to obtain the correct number of degrees of freedom. Line geometry is adopted to assist in the process. Additionally, the geometrical constraint equations of the robot are derived. The results in this work lay the foundation of the future research on inverse and forward kinematics, instantaneous kinematics, dynamics analysis and motion planning of this unique locomotion robot.

Sign in / Sign up

Export Citation Format

Share Document