ALGOR'S MECHANICAL EVENT SIMULATION SOFTWARE FOR MECHANICAL ENGINEERS ELIMINATES NEED FOR MOTION LOAD TRANSFER PROCESS

Algor's Mechanical Event Simulation (MES) software uses a single process to replicate motion and flexing (stresses), such as that occurring as these gears rotate, at each instant in time. Unlike separate kinematic or "motion-only" packages used for motion load transfer, MES can handle contact and impact between separate, interacting parts to determine forces and stresses as well as account for dynamic effects, such as resonance, which could lead to harmful clashing in a gear system.

April 15, 1999, Pittsburgh, Pennsylvania - Mechanical Event Simulation software from Pittsburgh-based Algor, Inc. eliminates the need for motion load transfer by using a single process to replicate motion, flexing and stresses of mechanical devices throughout a hypothetical "event." FEA-based Mechanical Event Simulation extends beyond motion-only simulations, used for motion load transfer, by handling flexible-body motion, impact and multiple physical phenomena.

The most comprehensive of Algor's Mechanical Event Simulation (MES) software, Accupak/VE replicates events using linear or nonlinear material models for complete Virtual Prototyping. Algor also offers Accupak/MES, which includes MES for linear material models. Both of these packages enable better, safer designs, reduce the need for physical prototyping and shorten time-to-market.

Multi-Step vs. Single-Step Processes
Unlike MES, which performs kinematics and FEA in a single process, motion load transfer requires the use of separate kinematic and FEA software packages. In the motion load transfer process, engineers use kinematic software to simulate rigid-body motion in fully coupled mechanisms and produce forces over time. Then the maximum force from the kinematic analysis can be used in static FEA to determine maximum stresses at one instant in time.

According to Michael L. Bussler, president of Algor, Inc., working with multiple packages can be inefficient and produce inaccurate results. "Using multiple packages is not practical for real work. Engineers exert a great deal of extra effort by repeatedly transferring results between kinematic and stress packages," Bussler said. "With Algor, engineers need only one software tool, Mechanical Event Simulation, to simultaneously produce motion, flexing and stresses."

The What-You-See-Is-What-You-Get process of motion and flexing simulations with MES reveals how a device will perform in the real world. Stresses are based on the physics of the event, eliminating the need to specify forces in the setup, and are displayed as they develop over time. Unlike the static FEA situations involved in motion load transfer, MES models bend, twist, stretch and squash due to motion. MES also handles contact and impact for simulating the interaction of independently moving parts of an assembly or separate objects, such as occurs in a rotating gear system.

"With MES, engineers can better see the cause-and-effect relationship among motion, flexing and stresses," Bussler explained. "They can determine whether the design will fail and see changes in shape or stress that may help them design a better product before initiating physical prototype testing."

Assumptions Remain with Motion Load Transfer
While MES eliminates the need for assumptions about force altogether, motion load transfer requires additional assumptions be made to determine forces in kinematic analyses. Engineers must assume that all motion is rigid-body motion and make assumptions about stiffness at all joints and links. For example, if a flywheel is connected to a rod by a pin joint, the joint experiences flexible-body motion as the rod spins the flywheel, resulting in flexing and stresses. Because motion-only simulations handle just rigid-body motion, forces determined at the joint may produce less accurate stress results when applied to FEA, as compared to MES which determines flexing and stresses directly from flexible-body motion.

Motion-only simulations only determine changes in motion for fully coupled mechanisms; therefore, they cannot produce forces or stresses from the interaction of two or more completely separate parts, as MES can. Dynamic attributes such as resonance and load stiffening cannot be handled by static FEA, whereas MES automatically accounts for these throughout an event.

Algor's MES packages also interface with CAD systems and offer special elements to reduce run times in performing MES on solid models and assemblies. Accupak/VE includes material models that capture real-world material behavior and can incorporate other Algor FEA processors to simulate forces from physical phenomena, such as heat transfer, fluid flow and pressure. Algor's MES packages are available for Windows 95/98 and NT workstations.

Algor has been a leader in the engineering software industry since it introduced FEA for PCs in 1984 and interfacing with CAD systems in 1985. The company recently celebrated 20 years of providing finite element users with innovative, affordable and easy-to-use software products and superior educational support and customer service. Algor's FEA software has enabled 16,000 engineers in 60 countries to create safe, efficient, cost-effective designs.

In addition to Mechanical Event Simulation capabilities, Algor software works within or alongside any CAD system. The company's new kinematic finite element technology makes it possible to perform Mechanical Event Simulations on CAD solid models or assemblies. Algor also offers advanced FEA meshing tools and a range of other FEA capabilities including linear and nonlinear stress, vibration and natural frequencies, heat transfer, electrostatics, fluid flow, piping design and composite materials.