Getting a Clearer Picture with Advanced Simulation Software
Smart Manufacturing Magazine May 2019
By Patrick Waurzyniak
The latest visualization systems enable manufacturers to design and make products faster and more efficiently than ever.
Simulation in manufacturing is becoming much more pervasive. Advanced visualizations are used everywhere, from machining on shop-floor CNCs to offline CAD/CAM programming of NC equipment. In the product lifecycle management (PLM) arena, product developers rely heavily on sophisticated multiphysics-based computer-aided engineering (CAE) applications at multiple stages of the design process to accurately determine if their creations will withstand a multitude of thermal, fluid, and material fatigue stresses typically encountered in harsh environments, such as automotive and aerospace, to ensure new product designs meet stringent quality controls.
The latest iterations of 3D visualization software packages give manufacturers ways to accelerate prove-outs of their manufacturing cutting and assembly operations, often with near 100 percent accuracy. That capability is essential for improving both traditional machining and new additive manufacturing process efficiencies.
More Precise Results
One major trend is the use of simulations that offer users much more precise results, using sophisticated tools to derive material properties, said Hendrik Schafstall, co-founder, managing partner and CEO of Hamburg, Germany-based Simufact Engineering GmbH, a business unit of Newport Beach, Calif.-based CAE developer MSC Software. Manufacturers can now get “a process chain simulation of all relevant process steps and related interfaces—mainly to capture manufacturing history for subsequent crashes and fatigue life, and to predict the local properties in the part for part performance,” Schafstall said. For OEMs, simulations have a fully automated coupling with PDM [product data management] systems, he added.
Another trend is to use more information from the manufacturing process simulation, which must be accounted for during the design phase, Schafstall noted. “A big driver is additive manufacturing and sheet assembly,” he said. There is also more use of the part “as manufactured” for structure simulation for more precise results, he added, and simulations have more robust process windows to detect the main influence parameters that must be monitored and controlled during production.
Increased practical “realism” and more advanced analytics capability remain key trends for all types of simulation, said Ben Mund, senior analyst, CNC Software Inc., Tolland, Conn., developer of Mastercam CAD/CAM software. Mund noted that today’s simulations offer users “a more deeply understood mathematical model of all of a machine’s moving parts, how they interact with the tooling and workpiece, and the ability to identify exactly where and why unwanted motion might happen. These areas are developing in tandem, providing more confidence for the programmer and more productivity on the shop floor.”
Accurate simulation is more important than ever in manufacturing, Mund added. “With the advent of increasingly complex machines, there’s a need for both high precision in NC programming and bulletproof confidence that a machine will run that program correctly,” Mund stated. “It’s also useful for shops to have different types of simulation depending on what they need. Toolpath-only simulation allows a quick and clean view of the cutter’s motion in the part, with deep analytics available at any point along the path. Machine-level simulation expands that approach by adding the machine environment, showing any potential conflicts from items moving within the machine itself.
“Simulation is becoming more critical to every shop; as machines and tooling become more advanced, the drive for productivity increases, and the need for connected feedback becomes more common,” he continued. “Realistic simulation is booming on all fronts. Deep mathematical simulation of interactions between machine, tooling, material, and intended final workpiece drive most of the practical applications a shop needs. This is the ‘core’ of simulation in which manufacturing software companies invest most of their heavy development and testing [budget].”
This new level of mathematical realism is enhanced and made more engaging with the addition of
“on-screen” realism. “This takes the physics models and makes them look as real-world as possible to the user,” Mund said. “Here you’ll see visual buildouts of machines and all their moving parts (occasionally including manufacturer logos), color and visual material choice, and other display options that let a programmer easily see and be confident in their program’s results.”
Accessibility to simulation tools has been a barrier for many people in manufacturing, as high-end simulations—especially in CAE—have generally been handled by highly trained simulation specialists. In recent years, however, greater access to these visualizations is being provided throughout manufacturing organizations. This access is provided by connections to host data systems, either via lightweight client apps or by leveraging the power of the cloud with high-performance computing (HPC) and bringing supercomputer-level power to bear on extremely large, complex visualization analyses.
“One of the key trends in simulation software is to continue to reduce the barriers to usage. Everyone accepts that simulation can provide valuable insights and save time and money, but there are often barriers to adoption,” said Brian Frank, senior product manager for generative design and simulation solutions at Autodesk Inc., San Rafael, Calif.
“Some of those manifest themselves in the cost and ability to access. Autodesk has worked very hard to make it easier than ever to access world-class simulation technology through our subscription offerings, and we continue to bring more of the technology into core design offerings like Fusion 360. We also continue to make sure users don’t need specialized simulation knowledge to get value from the act of simulating by automating and guiding users through the workflows they need to execute.”
The move toward digitizing manufacturing underscores the essential need to push simulation tools out to a wider audience to cope with the speed of today’s digital manufacturing/Industry 4.0 transformations, according to Ravi Shankar, global director of product marketing for Simcenter, Siemens PLM Software, based in Plano, Texas. Simulation is critical for companies that are digitizing their product development process because when the design and manufacturing process is simulated correctly in the virtual world, companies can get their designs to market faster.
Expanding simulation access is an important topic, agreed Shankar. “A significant amount of progress has been made in recent years,” he said, “but there is still a ways to go. We can view democratization as both the ability for more people within an organization to perform simulations and also for more people to consume simulations without having to be simulation experts.”
Siemens is at the forefront of this transformation, Shankar stated, due to its strength in serving the needs of designers. “Some examples of this include the integration of simulation technologies within the Siemens NX environment [which includes CAD/CAM and CAE capabilities]; integration of simulation capabilities in other commercial CAD offerings through our Simcenter FloEFD [Mentor Graphics’ computational fluid dynamics] solution; and also more broadly through our investments in generative design and visualization, including advanced VR methods for exploring simulation results.”
Cloud access to CAE solutions also added much-needed accessibility for non-expert simulation users in manufacturing. “Historically, manufacturing software and CAE simulation software have been disconnected niche products used by manufacturing engineers and simulation experts, respectively,” noted Subham Sett, vice president, Simulia marketing and strategic initiatives, at Dassault Systèmes, based in Waltham, Mass. and Vélizy-Villacoublay, France.
“However, with today’s [demands for] first-time quality with reduced production costs, companies are looking to leverage the benefits of simulating manufacturing processes before they are implemented. To do this, an integrated approach is needed to link the product BOM [Bill of Materials] to the manufacturing process—including realistic simulation of both.”
Dassault Systèmes’ 3DExperience simulation offerings on the cloud are definitely helping simulation become more democratized, Sett noted, because they “require only limited local hardware and IT support to access large amounts of computational power and simulation capabilities.”
CNC Software’s Mund added that “simulation has become democratized to the point where it’s an expected component of any CAD/CAM software offering. As general simulation became more widespread, the type and depth of simulation was also dramatically expanded. Over the last two decades, the industry has moved from basic toolpath backplotting to material removal visualization to complete simulation of the machine tool environment.” Users’ expectations about what should be available as a standard component of CAD/CAM have moved with it, said Mund.
“While exceptional stand-alone solutions remain—and have a vital place in many shops—simulation has become such an ingrained part of shop workflow that most CAD/CAM providers consider it almost as important as the tool motion itself,” he stated.
Investing in Simulation
Over the past several years, the largest simulation players—Autodesk, Dassault, Siemens, and now Hexagon—have made substantial investments in the simulation arena, particularly in CAE multiphysics applications. Siemens spent $4.5 billion to acquire electronic design automation (EDA) giant Mentor Graphics in 2016, and also purchased LMS International and CD-adapco to build its simulation portfolio. More recently, metrology giant Hexagon AB, Stockholm, Sweden, acquired Spring Technologies, developer of NCSIMUL toolpath simulation and verification software, in 2018.
“Siemens has been very active in acquiring and integrating solutions in the simulation space as a part of a larger focus on delivering a digital innovation platform,” Siemens’ Shankar said. “With Simcenter, we offer one of the broadest and deepest portfolios in the industry for simulation and test. This includes capabilities from our acquisitions of LMS and CD-adapco, which helped us expand in areas such as system simulation, advanced 3D simulation, testing, and fluid simulation, all of which we combined with solutions for design exploration and simulation data management.”
With Mentor Graphics, Siemens gained sophisticated capabilities in the electrical and electronics space, and also strengthened its offerings for the design engineer, specifically through CAD-embedded flow simulation, he added, noting Mentor’s hardware testing solutions are also a great addition to the portfolio. Also, in January Siemens released a full update of its Simcenter 3D platform, adding faster modeling and more accurate simulations.
“High-value customer applications in all industries increasingly require simulation capability for all physics, at all scales,” noted Dassault’s Sett. “To complement our existing strength in structures and multibody simulation, Dassault Systèmes recently gained a strong capability for fluids and acoustics simulation through the acquisition of the PowerFlow, XFlow, and Wave6 product lines. In addition, we have acquired the CST Studio suite product line, which provides a complementary capability for electromagnetics simulation.”
Improved Accuracy, Ease of Use
With expectations of attaining true digital twins in manufacturing operations, developers are delivering increased realism and accuracy. “CAE simulations for manufacturers today are extremely realistic and accurate, to the point where predicted manufacturing distortions can be used to negatively compensate a design, so the as-manufactured part is within required tolerances of the as-designed part,” Sett said. “In plain language, we can anticipate the distortion to the part shape due to the manufacturing process, then account for that distortion so the finished part matches the desired geometry.
“Simulation users are looking for accuracy, speed, ease of use and integration with manufacturing software,” he added. “Additionally, the manufacturing engineer requires simulation tools that are easy and intuitive to use, without an in-depth simulation background.” Additive’s use of simulation is also growing quickly, as the ability to create designs not possible in traditional manufacturing leads to a greater need to simulate design iterations. “Much of the cutting-edge simulation work in manufacturing is related to additive manufacturing,” said Sett.
In today’s connected, advanced manufacturing installations, simulation has much potential to speed designs to market, cut costs and minimize or eliminate manufacturing flaws. Simulation can lead to “a lot of different cost-saving potential, depending on the application,” noted MSC Software’s Schafstall, “as well as faster time to market, deeper insights, process understanding, and internal knowledge transfer.” Other advantages include additional potential manufacturing variations, with a more robust process window where more ideas can be proofed, he said.
Simulation offers users much more detailed information before production starts, he added. “A better understanding of the manufacturing process and its problems will help [create] a more manufacturable, optimized design,” Schafstall stated. “This also means the manufacturing simulation will move more and more in the design phase [in additive].”
In February, MSC Software released its new CoSim engine developed to provide a co-simulation interface for the direct coupling of different solvers/disciplines within a multiphysics framework. The CoSim V1.6 version enables engineers to set up co-simulation models between MSC’s Adams multibody dynamics (MBD), Marc (FEA), and scFLOW (CFD) applications, and covers a wide range of industrial-scale applications. The CoSim engine offers improved accuracy, precision and performance for complex multiphysics applications, according to MSC.
The high level of realistic accuracy has never been more achievable than with today’s offerings, according to Autodesk’s Frank. “With the compute power available today, we can capture insights into the manufacturing process like never before, and also design experiments to understand what combination of materials, process settings, and design parameters can be used to achieve the best results. Whether it be NC simulation for the operation of machines or process simulation of something like injection mold performance or an additive metal 3D print, users have the most insight into what they can expect on the shop floor,” Frank said.
He noted that Autodesk maintains its own production and testing labs, constantly evaluating its software for accuracy and predictability.
Simulating NC Cutting
In NC simulation, simulating and verifying cutting tool processes provides manufacturers with a clear picture of toolpath cutting motion, including all of the other moving elements in the machine tool besides the actual cutting tool. With the latest simulation and verification software from NCSIMUL Hexagon Production Software, Boston, users get a fully automated system that does a lot of the work, with new simulation automation features now being integrated into parent Hexagon Manufacturing Intelligence’s Vero Software lineup of CAD/CAM software, which includes the EdgeCAM, WorkNC, AlphaCAM and other Vero brands, as well as 15 third-party applications, including Mastercam and Siemens NX CAM.
An NCSIMUL 2020 update, which was slated for release in April, features much better integration with CAM systems through its application programming interface (API), an updated graphical user interface, and full bill of materials across production, including measurement and control, said NCSIMUL General Manager Silvère Proisy. An auto control capability helps improve the connection to CNC machines, he added, with the ability to read all of the parameters on the shop floor. “We connect the programmers to the shop floor,” he said, “so they don’t have to leave their computers. This is even more critical with five-axis machines that need CAV (computer-aided verification).”
The latest NCSIMUL system offers more realistic simulations, he added. “We cut volume to volume; you can see the scallops, see the true cut on the part,” Proisy said. “It’s really down to reality, with very fine detail. We are really automatizing the process, with templates that send your modifications to NCSIMUL, which runs the simulation in a black box, and shows if your program is safe or not safe. What’s new is the detail on how much automation we can do, and also new optimization for not just milling, which we added last year, but also for turning machines.”
Simulating and verifying the cutting process has never been more critical with the latest generation of machine tools. “Newer CNC machines are being made increasingly complex and faster moving than their predecessors,” noted Gene Granata, Vericut product manager at NC simulation/verification developer CGTech, Irvine, Calif. “Today’s machines have more moving parts, added capabilities, and many new M and G-codes required to make things work properly. Even a seemingly simple action like a ‘tool change’ happens at frighteningly fast rates. Catastrophic failure can come very quickly and unexpectedly when cutting tools and CNC machines are pushed to their ultimate limits.”
Optimizing NC codes and the processes used to create them is the focus for most NC shops, Granata said. “Decreased profit margins and increased competition are primary reasons for this; optimizing any way you can and accurate cost estimating are critical for business survival,” he added. “Using software like Vericut with Force optimization ensures all NC programs cut with optimal chip loads, keep dynamic cutting forces within safe limits, and enable more accurate machining time predictions.”
Accurate simulation is key to productivity, Granata said. “Simulating NC code run on digital twin machine models keeps CNC machines making parts instead of wasting valuable machine time on prove-outs. Using simulation, ‘virtually’ eliminates the potential crashes and machining errors that could cause serious problems in the shop, and thereby avoids costly downtime and schedule delays.
“Simulation can do a better job when more accurate data is accessible,” he continued. “For example, accurate machine models are desirable for precise detection of potential machine collisions. Similarly, detailed models of cutting tools help verify that part features can be reached with confidence during machining and are used properly [e.g. with safe ramping angles]. When cutting tools are downloaded from the cloud with recommended cutting performance parameters, programmers can also be assured they are using appropriate feeds and speeds for machining and for optimization.”
According to Granata, NC-level simulation on a digital twin CNC machine is viewed as the most comprehensive way to verify that NC programs will work well on the intended CNC machine and produce the machined part as expected, without encountering collisions, exceeding axis travel limits, or creating mishaps from incorrect or missing NC codes. “NC-level simulation is also the best choice for NC program optimization, because optimal cutting methods and the machine’s capabilities/limits can be
simultaneously applied,” he noted.
The latest Vericut version 9 uses more advanced OpenGL graphics capabilities to provide superior graphical display quality and performance, according to CGTech. The enhanced graphics improve function and consistency across views, enabling all the software’s functions for taking measurements, applying section cuts, and comparing the theoretical design model versus simulated cut part.
Some features coming for Vericut users include a new Restart capability, Granata said. “When a mistake is identified in an NC program, users can make corrections and restart the simulation a block or two before the error occurred, then play forward to verify the change is what they want.” Force optimizers will offer better-optimized machining and improved Force Chart interactions. There will also be a new Force Calibration product offering for shops that want to test their own tool-to-stock cutting conditions, and use the data gathered to drive Vericut’s Force NC program analysis and optimization.