For beam elements, midas Civil can analyze the displacements and the maximum stresses at the end nodes as well as at intermediate points (Results>Beam Detail Analysis).
For plate elements, thin plate (DKT, DKQ) and thick plate (DKMT, DKMQ) elements must be used appropriately. Accurate analysis results can be obtained from thin plates for structures such as common storage tanks. Thick plates may be more appropriate for modeling walls, bridge decks, basemats, etc.
The Tapered Beam Element formulated from the most current algorithms can precisely simulate the behavior of a hunched beam with varying section dimensions along the length. The Cable Element has also been introduced in midas Civil for the design of cable-stayed bridges with a small strain condition, and suspended cable structures with geometric nonlinearity including the sagging effect.
Analysis
The finite element library of midas Civil contains the following: Refer to
“Numerical Analysis Model ” of the Analysis Manual for details.
Truss
Transmit only tensile and compressive loads in the element axial direction Compression-only Truss/Gap
Transmit only compressive load in the element axial direction considering a gap distance
Tension-only Truss/Hook
Transmit only tensile load in the element axial direction considering a hook distance
Cable
Transmit only tensile load in the element axial direction considering varying stiffness due to the variation of the internal tension and the sag effect
General Prismatic Beam
Common beam element considering 6 degrees of freedom per node Tapered Beam
Beam element with varying sections along the length considering 6 degrees of freedom per node
Plane Stress
Plane stress element considering in-plane behaviors Plate
Plate element considering in-plane and out-of-plane bending behaviors Stiffened Plate
Anisotropic Plate element considering in-plane and out-of-plane bending behaviors
Plane Strain
Plane strain element considering 2-D behaviors in the GCS X-Z plane Axisymmetric
Axisymmetric element considering 2-D behaviors in the GCS X-Z plane Solid
Solid element considering 3 degrees of freedom per node
Visco-elastic Damper
Linear spring and (non) linear viscous damper combined in parallel and connected to a spring linking two nodes in all 6 degrees of freedom. An additional linear viscous damping coefficient for each dof in parallel with the system can be defined.
Hysteretic System
Hysteretic System consists of springs with the Uniaxial Plasticity property in all 6 degrees of freedom. An additional linear viscous damping coefficient for each degree of freedom in parallel with the system can be defined.
Lead Rubber Bearing Isolator
Similar to the Hysteretic System, it includes 2 inter-related shear deformation springs with the Biaxial Plasticity property. Independent linear elastic springs represent the remaining 4 degrees of freedom. An additional linear viscous damping coefficient for each dof in parallel with the system can be defined.
Friction Pendulum System Isolator
It includes 2 inter-related shear deformation springs with the Biaxial Plasticity property whose physical movements take the form of a pendulum (pot bearing). The axial deformation spring retains the property of a Gap spring with 0 internal gap. Independent linear elastic springs represent the remaining 3 degrees of freedom. An additional linear viscous damping coefficient for each dof in parallel with the system can be defined.
Analysis
Analysis
midas Civil provides three solvers for analysis. Select the analysis method from Analysis>Analysis Options. The default is the Skyline Solver.
The Skyline Solver is generally used in most structural analysis programs. It can be used in virtually all cases regardless of the types and scales of analysis models or the system capacities. It is an optimized algorithm that can analyze most structural engineering problems within a short time frame.
The Band Solver is more appropriate for an ABD (Almost Block Diagonal) stiffness matrix and can be used in all cases, similar to the Skyline Solver.
The high performance Multi-Frontal Sparse Gaussian Solver (MFSGS) is a latest addition to the group of MIDAS solvers. The MFSGS uses an optimum frontal division algorithm to minimize the number of calculations for simultaneous linear equations. The MFSGS is especially useful for those finite elements that contain a large number of degrees of freedom. Structures with many nodes can be solved over 3~5 times faster depending on the cases. The MFSGS is a particularly useful solver for the detail analysis of a structure consisted of plate and/or solid elements.
The analysis capabilities of midas Civil are as follows: Refer to “Structural Analysis” of the On-line Manual for details.
Static Analysis
· Linear Static Analysis
· Thermal Stress Analysis
Dynamic Analysis
· Free Vibration Analysis
· Response Spectrum Analysis (SRSS, CQC, ABS)
· Time History Analysis
Geometric Nonlinear Analysis
· P-Delta Analysis
· Large Displacement Analysis
Boundary Nonlinear Dynamic Analysis
· Gap
· Hook
· Visco-elastic Damper
· Hysteretic System
· Lead Rubber Bearing Isolator
· Friction Pendulum System Isolator
Buckling Analysis
· Critical Buckling Load Factors
· Buckling Modes
Moving Load Analysis
· Influence Line Analysis
· Influence Surface Analysis
· Moving Load Tracer
Heat Transfer Analysis (Conduction, Convection, Radiation)
· Steady State Analysis
· Time Transient Analysis
Heat of Hydration Analysis
· Thermo-elastic Analysis (Temperature stress)
· Maturity, Creep, Shrinkage & Pipe Cooling
Construction Stage Analysis
· Time-dependent Material Properties
· Boundary Group
· Static Load Group
Pushover Analysis
· Loading Applications as per Mode Shape and Static Load type
· Generation of Capacity Spectrums & Demand Spectrums
Other Analysis Features
· Calculation of Unknown Loads using optimization technique
· Analysis of structures reflecting support settlements
· Analysis of steel girders reflecting the section properties before and after composite action
Analysis
Eigenvalue analysis result of the completed model of Youngjong Br. (vert. 1st mode: 0.485 Hz)
Heat of Hydration analysis results of the pier top portion of an Extradosed PSC Box reflecting the construction stage/concrete pour sequence showing stress distribution
Construction stage analysis model created by FCM Bridge Wizard
Analysis