Solidworks integration makes it faster and easier
CosmosWorks 2003 from Structural Research & Analysis
With the acquisition of SRAC by Dassault Systemes in March 2001, enhanced practical and commercial integration of the Cosmos range of products with SolidWorks looked inevitable.
Indeed SolidWorks itself now ships with a basic set of finite element (FE) tools in the guise of CosmosXpress, using a simple wizard based approach to analyse individual parts in order to understand and improve designs as early as possible in the design process.
Cosmos clearly also offer a wide range of analysis tools that exceed the needs of the general design team.
CosmosWorks offers an extensive set of FE tools and is complemented by product bundles offering integrated motion simulation in CosmosMotion and computational fluid dynamics (CFD) in CosmosFloWorks.
CosmosWorks itself has two levels, professional (£6,500) offering linear static, frequency buckling, thermal, shell analysis, assemblies and gap analysis and Advanced Professional (£9,500) that adds non linear and fatigue capabilities.
The greater SolidWorks integration in the 2003 release make it both easier and quicker to use.
By using the SolidWorks Property Manager, dialog boxes no longer clutter up the graphics area and hide the model.
By using standard input fields, geometry selection lists for applying loads and constraints can be modified without exiting the input dialog box.
The direction of loads and restraints can also be previewed and direction modified before being applied.
Analysis inputs such as material, restraints, loads, mesh size and contact resistance can also be defined as parameters with values entered in a table enabling changes to apply to multiple studies.
By defining multiple values for each parameter, analyses can be batch processed allowing design variants to be rapidly compared.
Although constraints are applied directly to the model, analyses rely on generation of a mesh.
If the default mesh fails, multiple mesh iterations of different element size are attempted automatically.
The number of iterations and allowable element size variation can be defined.
In assemblies where parts can vary considerably in size, mesh quality is improved by the automatic definition of appropriate element size.
Visualisation of results has been improved in a number of ways.
Deformed shapes can be superimposed over the original model with control over colour and transparency of the SolidWorks part to achieve the desired effect.
Similarly the remainder of a part can be shown semi transparent in a section view and parts can be selected for inclusion in an assembly plot, allowing results to be viewed in context.
Contact and frictional forces can be plotted or listed for an entire assembly or selected faces in any defined coordinate system.
The position, number format, font and background transparency of the legend plot can be customised and maximum and minimum values are automatically superimposed onto the model.
In addition to exporting result plots as html files, 2003 results can be published as eDrawings.
This enables the compact result file to be viewed, rotated, zoomed and annotated in 3D by the extended design team even without access to SolidWorks or Cosmos.
FE is only as good as the definition of the load case, and the integration with Motion analysis allows the investigation of dynamics before defining the FE constraints.
Forces likely to be encountered in operation can be predicted in CosmosMotion and these reaction forces can be exported directly into CosmosWorks to predict stresses and deflections.
Although data can only currently be exported for a single point in time, the process can be repeated simply by selecting a new time frame.
Care must be taken in Motion to define SolidWorks model geometry as bearing surfaces so that CosmosWorks can distribute the forces and moments over the selected faces and edges.
Any constraints missing assignments are highlighted at the time of export.
Joints that were generated from SolidWorks mates automatically use the original geometry as the bearing surface.
Although standard SolidWorks functionality allows investigation of the movement of components including collision detection, CosmosMotion based on the widely used ADAMS software adds physics based motion simulation.
By applying motors and actuators, power consumption, linkages, cams, gear trains, springs and dampers can be studied.
An improved solver is used in the 2003 version and user enhancements include the opportunity to interrupt a lengthy kinematic solution.
Definition of 3D contact between multiple parts has been improved with contact containers and simulation of vibration isolating mounts and non rigid joints is possible with isotropic bushings that have both spring and damping characteristics.
Visualisation is improved with springs rendered in wireframe or shaded and result vectors with size proportional to their value.
As always, Motion allows plots of all parameters to be dynamically graphed as the mechanism simulation runs.
The final element in the analysis arsenal is computational flow dynamics.
Traditionally a highly complex exercise exclusively on UNIX and undertaken by specialists, Nika pioneered the opportunity for CFD to be integrated into the mainstream design process.
FloWorks was incorporated into the SRAC product line to replace their own Cosmos/Flow product and hence now appears in the SolidWorks line-up as CosmosFloWorks.
Whilst maintaining the focus on ease of use, significant new functionality has been added in 2003.
Non-newtonian liquids can be modelled based on predefined viscosity models enabling real liquids such as tooth paste or blood to be simulated.
Heat transfer by radiation from and/or between solids can be considered and automatic convergence control aims to ensure stable solver convergence.
Visibility of goals also aids understanding of convergence behaviour.
The Cosmos suite of analysis tools makes significant testing of virtual prototypes possible.
This can greatly increase the value of 3D CAD models by reducing the number of time consuming iterations of physical prototypes and enabling the exploration of a wider number of design alternatives.
As always care must be taken in analysing results in this virtual world, particularly as increasing ease of use make it possible for any designer or engineer to generate a credible looking study.
With careful consideration of the problem and judicious use of confirmatory calculations or empirical testing, analysis tools will enable design issues to be highlighted and solutions optimised much earlier and more cost effectively.