Using Femap to make parts suitable for deep-space missions

Product: FEMAP, Simcenter
Industry: Aeroespacial

Siemens Digital Industries Software solution helps Almatech optimize unprecedented high-performance, lightweight component designs

Using Femap makes it easy to reiterate the simulation process.

Dr.Luc Blecha,CTO Almatech

Top precision and maintenance free reliability

To boldly go where no human has gone before was the mission of the starship Enterprise. Its aim was to explore strange new worlds, to seek out new life and new civilizations. While manned space voyages of this magnitude remain fictitious, mankind is sending out space probes to achieve these goals.

During their deep-space missions, typically lasting several years, the satellites are exposed to extreme environmental conditions. These include temperatures ranging from −160 °C to more than 350 °C and acceleration forces amounting to several g as well as high levels of various kinds of radiation. At the same time, there are no gravitational effects such as thermal convection. The on-board instruments and associated fixtures require high precision and operational reliability.

“Although they are optimized for minimum weight, their stability and functionality need to be sustained over several years without any maintenance or cleaning,” says Dr. Luc Blecha, chief technical officer (CTO) of Almatech. Employing 25 scientists and engineers, the company based in Lausanne, Switzerland, develops lightweight structures and mechanical solutions for exceptional requirements such as high precision and reliability in harsh environmental conditions. Almatech is frequently involved in the design of components for spacecraft programs of the European Space Agency (ESA).

Structural components for outer space

Scheduled for launch in late 2019, the Characterising Exoplanet Satellite (CHEOPS) will observe individual bright stars that are known to host exoplanets. It uses a photometer on its telescope to measure the dimming of the starlight caused by a transiting planet. It will provide scientists with the high-precision transit signatures that are needed to measure the sizes of small planets. This data will provide key insight into the formation and evolutionary history of planets.

As part of the Swiss-managed CHEOPS project, Almatech was in charge of all the structural components. The task involved the design and construction of the tubular main structure made of carbon fiber reinforced plastics (CFRP) as well as titanium brackets and the junctions holding the primary and secondary mirrors. The mirrors cannot be adjusted in flight, so their support needs to be rigid and have high stability over the range of temperatures experienced in space.

BepiColombo, a joint European and Japanese mission to Mercury, is already on its way to our inner neighbor. Launched in October 2018, it will start orbiting the least understood planet in our solar system in late 2025. The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). While gathering data during its one-year mission, the MPO will endure temperatures in excess of 350 °C.

Almatech designed and optimized a baffle that protects the MPO against heating to more than 270°C. It also protects the laser receiver of a built-in altimeter against the heat coming from the sun. The components included a very fine aluminum mirror used to deflect rays of sunlight. “The shape of this mirror was given, the tolerable roughness was specified at 4 nm, regardless of any external influences,” says Blecha. “By comparison, the diameter of one aluminum atom is 0.25 nm.”

The Solar Orbiter is a collaborative mission between the ESA and the United States’ National Aeronautics and Space Administration (NASA) to study the sun and its outer atmosphere. Scheduled for launch in 2019, the spacecraft will observe the sun’s atmosphere and combine these observations with measurements taken in the environment surrounding the orbiter. It will provide insight into fundamental physical processes studied under conditions that are impossible to reproduce on Earth and unfeasible to observe from astronomical distances.

A Spectral Imaging of the Coronal Environment (SPICE) instrument aboard the Solar Orbiter will observe both the solar disk and the corona to characterize plasma properties at and near the sun. For this instrument, Almatech designed a slit-changing mechanism. It moves the shutter by deforming parts rather than sliding along guiding tracks. “This is vital because particles created by abrasion would over time disable the optical instrument, and cleaning is impossible,” says Blecha.

Testing the digital twin again and again

For many parts, Almatech’s role is to optimize existing designs. The CHEOPS telescope structure, for instance, needed to be reduced in complexity and weight while retaining its structural strength. “Because all components we create are unique and need to function for many years without any maintenance or cleaning, development cycles take longer than in terrestrial designs,” says Blecha. “Although the shape of the baffle for the BepiColombo orbiter was given, it took us four years to arrive at the final hardware.” Almatech spent a similar period developing the slit-changing mechanism for the Solar Orbiter, although they were contracted to provide the entire development from first idea to final hardware.

The main cause for these extended development cycles is the enormous number of tests performed to deliver proof that all requirements will be met in all fathomable situations over the entire lifecycle of the components. Within a development cycle, several physical prototypes are built and tested as well, but Almatech performs the vast majority of these tests in the virtual world using a digital twin of the component under scrutiny. For this purpose, the space-grade equipment designers use Femap™ software from Siemens Digital Industries Software in conjunction with the Nastran® solver to simulate performance, starting at very early phases of product development. “The various model analyses provide proof to clients and authorities that the complex devices will perform as required under the anticipated conditions,” says Blecha. “They are also instrumental in our efforts to reduce mass without compromising stability.”

Pressure equipment design specialist Ener Consulting achieves reliable results using Simcenter Femap

Product: Femap, Simcenter
Industry: Industrial Machinery and Heavy Equipment

Ener Consulting automated the finite element analysis of pressure vessels in conformity with European and international standards

Verifying designs of pressure equipment

Ener Consulting – Integrated Technical Services (Ener Consulting), founded in 2002 and with headquarters in Prato, Italy, offers engineering consulting to industrial customers. The company’s mission is to work with dedication, to stay abreast of technological developments and to provide customers with reliable results. One of the core services of Ener Consulting is the verification of pressure equipment, exchangers, piping and vessels in the oil and gas, power and chemical industries. Over the years, the business has been gradually extended to other industries, including pharmaceuticals, food, pulp and paper, waste processing and many others.

“The design of pressure equipment has evolved over time for the type and complexity of analysis, requiring high-level specialization and analysis skills,” says Stefano Milani, finite element modeling (FEM) manager at Ener Consulting. “Until the mid-1990s, finite element analysis was regulated by loose standards; there were just a few guidelines with no proven procedures. Customers did not have extensive know-how, and without clear procedures, virtually all verifications of pressure vessels were based on manual calculations.”

Automated analysis with  Simcenter Femap

In the 2000s, the pressure vessel sector made quick progress with the introduction of standards and technology tools to automate analysis tasks. In this context, Ener Consulting started to collaborate with a Siemens Digital Industries Software Solution Partner for Simcenter 3D, Simcenter Femap and Nastran solutions. After using basic FEA software that could not perform accurate analysis and deliv-ered unreliable results, Ener Consulting identified Simcenter™ Femap™ with Nastran® software from Siemens Digital Industries Software as a suitable solution for implementing engineering, analysis and design services, and keeping up with the requirements of target markets.

“Traditional FEA tools that are integrated in 3D CAD software are very simple and intuitive,” Milani says, “but they have limited capabilities and are inadequate to execute accurate analysis in conformity with the strictest standards or in-depth verification. Simcenter Femap offers clear and tangible benefits in terms of speed, ease of use and reliability of results.”

The analysis conducted by Ener Consulting begins from 3D models with relatively complex geometries that are difficult to address with general-purpose FEA software. With Simcenter Femap, Ener Consulting engineers can readily clean the geometry, eliminating unnecessary features for analysis purposes (defeatur-ing). Alternatively, the equipment to be analyzed can be modeled directly in Simcenter Femap as a mesh.

Ener Consulting, developed an add-on module for stress linearization in Simcenter Femap. “With this plug-in, engineers need only a couple of clicks on the screen to get the results they are looking for,” says Francesco Palloni

“The end customers in our reference markets need to check products with a quick and reliable method,” Milani says. “Simcenter Femap helps us deliver the desired results following either a tradi-tional approach or a more modern and advanced method.” The benefits of nonlinear analysis

For the structural verification of pressure vessels, a traditional design-by-analysis approach (stress categorization) often results in component oversizing, because the conventional linear static analysis approach, while proven and easy to apply, is conservative. Engineers must also consider that the linear analysis procedure is articulated and time-consuming when applied to complex geometry. Currently, pressure equipment regulations allow the application of more accurate analysis methods, including using tools such as Simcenter Femap with Nastran for non-linear calculations.

“The ASME boiler and pressure vessel standard, for instance, allows for checking pressure vessels using a nonlinear consti-tutive equation,” Milani explains. “On one hand, it forces the analyst to introduce a more complex constitutive equation in the mathematical model; on the other it requires a tool like Simcenter Femap with  Nastran to solve this type of analysis,” Milani explains.

“The Simcenter Femap nonlinear approach offers a wider admissibility range,” Palloni adds. “With the same geometry and materials, a component can offer higher performance than those predicted with elastic linear analysis. Another benefit is obtained in the postprocessing phase, which is faster and immediate.”

The effectiveness of the Simcenter Femap nonlinear approach was proven in the case of a vessel with a flat bottom of variable thickness. When analyzed with a conventional linear analysis procedure, the component did not pass the elastic test; however, it proved suitable and compliant with applicable standards when it was checked with a nonlinear approach.

The linear approach to pressure vessel verification is constrained by significant design loads which, combined with linear stress analysis methods, results in the noncompliance of the design.Consequently, the initial geometry has to be modified or the load values have to be reduced to fit into the admissible range. Using Simcenter Femap with a nonlinear analysis approach requires more computing power than linear calculations and greater attention to plastic collapse, but offers a more immediate verification of the structural integrity of the pressure equipment.

IHC Handling Systems improves virtual prototypes and ultimate quality of offshore equipment; tight integration of Simcenter Femap and Solid Edge makes it possible

Product: Femap, Simcenter
Industry: Consumer Products and Retail

With Simcenter Femap, company increases re-use of proven designs, boosting productivity and decreasing costs.

The need for virtual prototypes

In the offshore industry, operational certainty is one of the most important requirements. The installations are large and the investments are high. Virtually everything is unique and leaves little room for error. As a supplier of tools for the installation of offshore equipment, IHC Handling Systems v.o.f. (IHC Handling Systems) is very familiar with the market. Functionality and quality must be validated prior to production. Virtual prototypes are the only way to ensure this.

IHC Handling Systems is part of IHC Merwede, a world leader in the dredging and offshore industry. IHC Merwede’s products include dredging vessels, equipment and components, as well special-purpose vessels and technology. IHC Handling Systems focuses on products for oil, gas and wind, such as equipment for pipe laying, equipment for the installation of oil and gas rigs and equipment for the installation of offshore wind mills.

Quick response and communication

In order to lay pipelines on the seabed or put piles of windmills upright, the thin-wall, tubular pipes need to be picked up by grippers. These are metal clamps that are placed on the inside and outside of the tube. The force with which the clamps grip the steel enables the lifting of the product. For the leveling of oil rigs, IHC Handling Systems provides equipment to establish a temporary connection between the seabed construction and the jackets on which the platform rests. Most of the products produced are project-specific. IHC Handling Systems usually has an early involvement in new offshore projects. “Customers approach us because of our reputation and experience,” says Cor Belder, concept engineer at IHC Handling Systems. It is important to have certainty about the concept solution in an early stage. A quick response to customer demands and communication are essential. “At the same time, we also want to offer functional certainty. That can only be achieved using advanced and integrated design tools.”

Lower cost of software

A few years ago, IHC Handling Systems purchased licenses of Siemens Digital Industries Software’s Solid Edge® software, a comprehensive hybrid 2D/3D computer-aided design (CAD) system, and Algor® Simulation software (which is currently owned by Autodesk and is offered under the name Autodesk® Simulation Mechanical) for finite element analysis (FEA). Both solutions were bought through Bosch Engineering, a Siemens Digital Industries Software partner. “Together with a sister company in the IHC Merwede group, we were forerunners in using Solid Edge,” says Belder. “Algor worked nicely together with Solid Edge, and data transfer between the two applications allowed for quick analysis of design alternatives.” But in a recent reassessment of the computer-aided engineering (CAE) applications, Belder saw room for improvement, specifically in the areas of data integration, meshing and programming.

“Early on in the evaluation, we developed a preference for Simcenter Femap,” says Belder. “Simcenter Femap offers a significant improvement in functionality over Algor at lower software costs. We want to spend our time on the evaluation of alter-native designs and don’t want to lose it over issues related to data transfer. Simcenter Femap and Solid Edge are tightly integrated, which saves time and reduces risk.” Belder notes that in addition to the robust geometry exchange, the mesh is more constant and allows for better local refinement.

Fast iterations

In a typical project, the concept engineer develops new models or combines and re-uses existing ones. “Concepts are almost always modeled in Solid Edge,” says Belder. “In the early stages, these are simplified designs focused on functionality, but ready to be used in preliminary CAE analyzes. The integration of Simcenter Femap and Solid Edge allows for fast iterations in this concept phase.” These functional concept designs are also used for client communication.

IHC Handling Systems uses both the linear and the nonlinear functionality of the NX™ Nastran® software solver embedded in Simcenter Femap™ software. The linear functionality is used for all static calculations as well as for contact analysis. Contact analysis is often used for designing lifting tools, where steel friction pads are pressed on the inside and outside of the pipe or pillar using hydraulic cylinders. The nonlinear analysis is used for the calculation of the friction between the steel pillar and the friction pads. This friction is the basis of the grip needed to lift the pillar or pipe. The amount of friction is defined by the pressure exerted on the cylinders. At the same time, the pressure should not lead to deformation of the pipe. “These are complex calculations taking up to 20 hours,” notes Belder. “We need to find the technical and economical optimum, in other words, the functionality must be ensured at the lowest cost possible. We take the calculations to the elasticity limit of the material.”

Re-use of proven designs

The re-use of meshes and load cases saves IHC Handling Systems a lot of time, especially in projects where existing concepts can be used, even though there may be many possible variations. An example is the upending tool that is used for lifting pillars. Upending tools must be able to handle many different diameter/wall thickness combinations and must be able to pick up pillars with diameters up to 6,000 millimeters. The customer specifies the diameter of the pillar and the lifting capacity of the available crane. To find the most economical solution, the engineer would traditionally select variants and perform the necessary calculations. This implies that, for every variant, the generation of the mesh and the application of the load case are required to perform a single calculation. The geometry of the variants differs too much to re-use the mesh and load case.

Using the programming capabilities of Simcenter Femap, the CAE model can be configured and generated automatically, for example, from Excel® spreadsheet software, including the mesh and the load case to be analyzed. Moreover, programming with Simcenter Femap is easy to learn. “Using the traditional way of working, we would be able to analyze only three combinations a day,” says Belder. “Programming in Simcenter Femap saves us a significant part of the time needed for modeling, meshing and applying the load case. The preparations can be reduced from hours to minutes. We can respond much quicker to changing customer requirements.” According to Belder, building the application of the upending tool took, all in all, no more than a week: “The investment has already paid for itself, because we always need to do calculations in projects for upending tools, which we use often in our projects.”

The goal to work better, faster and more cost-efficient using Simcenter Femap has been achieved. “We were satisfied with the engineering tools we had, but there is always room for improvement. Using Simcenter Femap allows us, better than ever before, to serve our customers with our experience and quality,” concludes Belder.

Jet Propulsion Laboratory NASA engineers used Simcenter Femap to ensure Curiosity could endure the “Seven Minutes of Terror”

Product: Femap, Simcenter
Industry: Aerospace and Defense

Simcenter Femap helps optimize component and parts for Curiosity’s mission to Mars, the most challenging and demanding ever.

Sending a package to Mars is a complex undertaking

Delivering a roving science laboratory from Earth to the planet Mars requires meticulous planning and precision performance. You only have one chance to get it right: there’s no margin for error. Engineers and scientists at NASA’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology had to make crucial decisions thousands of times over a multi-year product development schedule to successfully land the Mars Rover “Curiosity” on the floor of Gale Crater on August 6, 2012.   They’ve been doing rocket science at JPL since the 1930s. In 1958, JPL scientists launched Explorer, the first US satellite to orbit the Earth, followed by many successful missions not only near Earth, but also to other planets and the stars.

JPL engineers use a toolkit of engineering software applications from Siemens Digital Industries Software to help them make highly informed decisions. A key component in this toolkit is Simcenter™ Femap™ software, an advanced engineering simulation software program that helps create finite element analysis (FEA) models of complex engineering products and systems and displays solution results. Using Simcenter Femap, JPL engineers virtually modeled Curiosity’s components, assemblies and systems, and simulated their performance under a variety of conditions.

From 13,000 to 0 mph in seven minutes Also known as the Mars Science Laboratory (MSL), this rover is massive compared to earlier vehicles NASA has landed on the “Red Planet.” In the deployed configuration with the arm extended, the rover is 2.5 meters wide, 4.5 meters long and 2.1 meters high. Weighing nearly a ton, the Curiosity rover is five times the mass and twice the length of its predecessors, which meant that an entirely new and much softer landing procedure had to be engineered. NASA needed to slow the rover spacecraft from a speed of 13,000 miles per hour (mph) to a virtual standstill to softly land the rover during what NASA calls “Seven Minutes of Terror.” After completing a series of “S” maneuvers, deploying a huge parachute, and then with the unprecedented use of a specially designed “sky crane,” the MSL was gently set down so as not to damage the labs’ functional and scientific components.

Those components include a 2.1 m long robotic arm, which is used to collect powdered samples from rocks, scoop soil, brush surfaces and deliver samples for analytical instruments. The science instruments on the arm’s turret include the Mars Hand Lens Imager (MAHLI) and the Alpha Particle X-ray Spectrometer (APXS). Other tools on the turret are components of the rover’s Sample Acquisition, Processing and Handling (SA/SPaH) subsystem: The Powder Acquisition Drill System (PADS), the Dust Removal Tool (DRT), and the Collection and Handling for Interior Martian Rock Analysis (CHIMRA) device.

Curiosity also inherited many design elements from the previous Mars rovers “Spirit” and “Opportunity,” which reached Mars in 2004. Those features include six-wheel drive, a rocker-bogie suspension system and cameras mounted on a mast to help the mission’s team on Earth select exploration targets and driving routes on Mars.

Virtually all of the spacecraft itself and its payload were subjected to simulation analysis using Simcenter Femap for pre- and post-processing. Simulations performed before part and system production included linear static, normal loads, buckling, nonlinear, random vibration and transient analyses. Thousands of design decisions were made using information from Simcenter Femap simulations.

In addition to the complex nature of the mission itself, engineers developing Curiosity from initial design to final delivery of components to Cape Canaveral were working against the clock. The ideal time window to send a package from Earth to Mars is a 2- to 3-week period that happens roughly every 26 months. Missing that window would have set the mission back by more than two years, so JPL engineers needed to analyze parts and components quickly and efficiently so that they could be fabricated.

The role of Simcenter Femap

Simcenter Femap is JPL’s primary pre- and postprocessor for FEA. For MSL, engineers started using Simcenter Femap early in the design stage when they were performing trade studies on various configurations or different ways to approach the mission. As the configuration matured, they used Simcenter Femap to help create the master finite element model that was used to run the various load cases.

Most of the structural analysts at JPL use Simcenter Femap either for creating or viewing the results of a FEA run. The software was used for both high level-linear analysis and very detailed nonlinear analysis. These are two very different types of analysis both using the same piece of software.

Certain jobs were simply too large for one person, and in some instances engineers had to build on the work of other people who had previously used Simcenter Femap to build FEA models. Simcenter Femap was designed as a very easy-to-use package, created for analysts by analysts who are acutely aware of what engineers need and how they work. They can pick it up after six months of non-use and be back to peak proficiency in a very short time.

Simcenter Femap was critical in performing all types of FEA on all aspects of the vehicle. Each component of the vehicle had a higher-level, loads-type model built, and these models were joined to create the full spacecraft model. JPL engineers worked through various “what if” scenarios, including as many as 37 different load cases for how the parachute would deploy during the landing process.

The Curiosity mission is not JPL’s only current project. Other missions include satellites monitoring conditions on Earth, telescopes, experiments and other spacecraft.

Planned missions include the InSight mission that will place a lander on Mars in 2016 to drill beneath the surface and investigate the planet’s deep interior to better understand Mars’ evolution. There are even plans for a proposed Mars Sample Return mission, which would collect samples from the surface of Mars and return them to Earth.

JPL engineers are currently using and will likely continue to use Simcenter Femap to help accomplish these and other missions of engineering, discovery and science.

Startup Exept uses Simcenter Femap with Nastran to develop monocoque frame for road bikes in a virtual environment

Product: Femap
Industry: Consumer Products and Retail

Siemens solution enables EXEPT to go from concept design to product launch in less than a year

Developing the custom monocoque

Until recently any cyclist who wanted to buy a new bicycle had two options: Either purchase one of the big brands with a monocoque frame that is available in a fixed range of sizes with performance based on stiffness by weight, or a tailor-made frame manufactured with the tube-to-tube technique. This kind of bike has tubes that are cut, welded and wrapped with carbon fiber around the joints (knots), with the inevitable drawbacks in stiffness.

Now the Italian startup EXEPT, which is based in Savona, is providing a third way. It has developed a process that combines the benefits of both traditional approaches to create tailor-made monocoque frames. The custom monocoque technique invented by EXEPT uses movable molds to cast monocoque frames without any carbon fiber dis-continuity so it can be made to order for each cyclist.

“The key to economic sustainability in bike production is the cost of tooling,” says Alessandro Giusto, who is the co-founder of the company and the innovation and simulation manager. “A mold may cost up to €50,000 to 60,000, therefore only the big brands can reach volumes large enough to make a mold for each size. Instead, we have developed an innovative technology to build all sizes with one adjustable mold.”

The biggest Italian brand makes 15,000 high-end bikes a year, while EXEPT’s business plan calls for producing up to 3,000 pieces annually in five years.

All-round expertise

The movable mold concept was developed by the three founders and reflects their passion for bicycles. Giusto previously worked at Continental, a global leader in tire manufacturing, and also had experience in aerospace and the design of car-bon components for the sporting goods business. The second business partner, Alessio Rebagliati, is a colleague from Continental, while the third founder, Wolfgang Turainsky, is a German engineer who used to work for a Spanish manufacturer of bike components.

It took two years and two prototyping cycles to make prototypes that proved the feasibility of the custom monocoque process. Prior to being analyzed with simulation and finite element method (FEM) tools, the first frame was given to a former cycling professional for testing. Once the firm received his technical approval, EXEPT presented the project to an investment fund (Focus Futuro), which provided the necessary resources to move on to detailed design, testing and certification.

“The bike was designed from the very start according to the new concept,” Giusto says. “However, we did not focus on car-bon fiber initially, as composite material design is a complex activity that is a full-time job. Once we got the funds to finance our innovative idea, we could quit our previous jobs and plunge into the new enterprise.”

The pretest on the first prototype in May 2018, which was developed with just three months of design, confirmed the results of simulation and reassured Giusto and his partners they were ready to launch the bicycle at the Eurobike show in July, 2018.

Foolproof decision

In his experience in engineering companies in the aerospace and sporting goods industries, Giusto had the opportunity to learn and appreciate Simcenter™ Nastran® software, specifically the finite element modeling, and the pre- and postprocessing environment of Simcenter Femap™ software from Siemens.

“In aerospace, Simcenter Nastran is a de facto choice and we also used Simcenter Femap in our company,” Giusto remembers. “In six years, from 2007 to 2013, I acquired advanced skills with these tools, then I was in charge of the calculation department at Continental, where nonlinear analysis is performed using totally different tools.”

As a result, when the EXEPT project began, Giusto immediately reactivated his contacts with Siemens. “We did not need comparative analysis or benchmarking,” he says. “I knew we needed Simcenter Nastran, and the quality/price tradeoff for Simcenter Femap was excellent. All I had to do was call Siemens to explain our requirements and get an adequate offer, which we accepted immediately.”

EXEPT purchased a node locked bundle that incorporates Simcenter Femap with Nastran Basic in a single, integrated solution.

The EXEPT team initially worked with pencil and paper, proceeding by increasing levels of complexity to identify the loads that acted on the structure. The next stage was the development of the first simplified FEM model.

“We made a very simple model; in aero-space, they call it Global FEM, which is made up of one-dimensional elements (bars), and we investigated the load properties of these tubes in different riding, braking and impact conditions,” Giusto explains. “This approach is very useful as it provides quick feedback for each frame section. Then we moved on to a model of isotropic material, simulating an aluminum frame with constant thick-ness, and using the information from the Global FEM, we identified where we should decrease or increase the cross sections to optimize stiffness and weight. Finally, we worked on the geometry, which was re-meshed with four modifications to increase stiffness by 27 percent. This was done by just addressing the geometry!”

The carbon challenge

After optimizing the frame stiffness, the EXEPT’s engineers focused on carbon design. To define the ply book, also known as the lamination sequence, Giusto adjusted the structure 82 times, achieving extraordinary results.

“Compared to the initial stiffness of the nonoptimized prototype, we increased torsional stiffness by 150 percent while increasing the monocoque weight by only 12 percent,” Giusto says. “In this phase, Simcenter Femap offered huge benefits in terms of time and costs, enabling us to test and analyze the layering and direction of fibers only in the virtual domain, without increasing the quantity of material used.”

EXEPT executed an in-depth comparative analysis of the performance of more than 800 stock frames (in stan-dard sizes) developed and sold in the past three to four years in order to identify and achieve high-end stiffness and weight targets.

“The first nonoptimized frame we made was the third-best in terms of stiffness out of 800 frames we analyzed,” Giusto says. “We pushed stiffness so far that we decided to reduce it afterwards for road tests, to find the best tradeoff between stiffness and rideability. You know, reducing an optimized parameter is much easier than increasing it.”

At the end of June 2018, the excellent performance of EXEPT’s custom monocoque and the reliability of Simcenter Femap simulations was confirmed and certified with tests by an independent German laboratory: The deviation between real test and simulation was below 5 percent.

Giusto highlights how using Simcenter Femap accelerated the development of new frames: “We purchased Simcenter Femap with Nastran in September 2017 and started to laminate carbon in January 2018, delivering the ply book at the end of March. With Simcenter Femap, it took less than three months for over 80 iteration cycles. Just consider the average lead time for a brand bike is two years. We launched our model in July, having started to work on it less than one year before.

“All of this was possible only thanks to simulation; we made no physical iterations. No one in the cycling industry in Italy currently has comparable tools. At the beginning we contacted the engineering departments of big brands to present our concept; they have a conventional approach because they never develop a frame from scratch. They start with the expertise of their carbon supplier and rely on external partners for the subsequent development.”

Combining software and services

Giusto has no doubts when asked to list the key benefits of Simcenter Femap: “The key success factor is postprocessing. Simcenter Femap is definitely the best of all postprocessing engines I have used in my career. Simcenter Femap with Nastran has a complete environment for linear stress analysis of composites structures, which is suitable for our tasks. The Siemens software allows us to query the model and extract as much information as possible from structures like our frames; for instance, using free-body analysis to identify the interplay of forces inside the structure.”

The clear and intuitive visual display of Simcenter Femap helps the user under-stand the model better and provides advanced reporting tools for data extraction. As a result, the model construction is intuitive, fast and lean. “When I started to work full time with Simcenter Femap and Simcenter Nastran to simulate our frames, I did not start from scratch, but still I needed some training to refresh my memory after seven years using different software. Anytime I have a problem, I just have to pick up the phone and the engineers are always ready to answer questions to my full satisfaction. They can indicate the best way to approach analysis with a limited budget while using the best-fitting software configuration for our needs, regardless of the situation.”

With the advanced FEM capabilities of Simcenter Femap, EXEPT can execute sophisticated and critical simulations, static and dynamic tests, and simulations of complex mechanical events like falling and impact.