Engineering a Modern Amphitheater Velarium with SOLIDWORKS Solutions

Sdei Ouest

Sdei Ouest

Not since the days of Caesar has a velarium—a large, canvas canopy—adorned a coliseum-style amphitheater in Europe. Until now.

SDEI Ouest, an engineering consulting firm based in Cholet, France, undertook the challenge of designing, building, and installing the first velarium since the fall of Rome at the Gallo-Roman stadium at Puy du Fou in Vendée, France. Puy du Fou Park Managing Director Laurent Albert tasked SDEI Ouest with studying the feasibility of building a velarium atop the stadium, as well as with designing the structure and managing the project.

One of the project’s challenges involved developing a structure to withstand atmospheric conditions. The work required installing a huge, bicycle-wheel-like structure horizontally atop the arena to support the canopy. Made of steel beams welded together, the structure’s outer circle compresses to sustain loads of up to 200 metric tons. The inner circle—a set of cables and connecting rods—works in the opposite way, by traction, and connects to the outer circle by 288 spoke like radial cables.

Initial dynamic surveys showed that the inner circle could flap over in high winds, generating unacceptable loads on the surrounding wall. To develop a solution, SDEI Ouest chose to leverage SOLIDWORKS ® Premium design and SOLIDWORKS Simulation analysis solutions from Dassault Systèmes SOLIDWORKS Corporation.

“This project was complicated as it required the involvement of a whole range of professions including the field of mechanics, metals and textiles, steel frameworks, cabling, etc.,” explains SDEI Ouest Manager Bruno Fradet. “With SOLIDWORKS we were able to quickly and easily update the design and make numerous iterations throughout the design process, which has enabled us, in the allotted time period, to arrive at the finished solution, one which complies in full with the initial specification.”

Using SOLIDWORKS design and analysis tools, SDEI Ouest developed a solution: affixing12 vertical cables to the inner circle and anchoring them to the ground to increase rigidity. “SOLIDWORKS has been a fundamental asset in the success of this major challenge,” notes SDEI Ouest Head of Product Design and Calculations Yves Biret.

Addressing loading and safety concerns

With SOLIDWORKS solutions, SDEI Ouest satisfied the highly specific and stringent safety standards for the velarium, as well as meeting additional requirements involving weight, cost, and aesthetics. Key constraints included safety regulations for public buildings, maximum weight, an accurate cost point for the canvas, architectural aesthetics, wind resistance to gusts over 70km/h (43mph), rain and sun resistance, deployment in less than one minute, and an operational deadline of April13, 2011.

By using SOLIDWORKS Simulation software, SDEI Ouest not only avoided costly prototyping but also quickly assessed design response to loading conditions. For example, the regulatory authority overseeing the project increased the radial load requirement by 62 percent midway through the project. Conducting simulations on the vertical cable clamp allowed SDEI Ouest to quickly address these new parameters, while also reducing clamp weight by 24 percent.

“SOLIDWORKS Simulation is just what we needed,” Biret stresses. “The proof lies in the strong correlation between reality and simulation.”

Automated approach results in patents

Design iterations in SOLIDWORKS helped SDEI Ouest develop technical innovations for deploying, folding, and storing the velarium, for which it has secured two patents. An automated system unfolds the velarium during deployment and folds the canvas sections for storage when the velarium is not in use.

“This project let us design innovative, patented processes such as the motor systems allowing144canvassectionstobeunfoldedandthenstoredawayinenclosures,plus the mechanical strap system that partially releases the canvas in the event of exceptional gusts of wind,” Biret points out. “This has been a major challenge for SDEI Ouest as it has occupied more than half of our teams. But it has been a resounding success, thanks in part to the SOLIDWORKS solutions from Dassault Systèmes and to our own expertise. A world first that has given us a reputation to match the challenge.”

Facilitating design Communications

The SOLIDWORKS 3D model streamlined communications among project partners, greatly facilitating production and assembly of the velarium’s 8,800 components.

A wide range of considerations—including metallo-textile structures, wind effect simulations, concrete structures, metal frameworks, automated mechanisms, water impacts, plastics processing technologies, and aesthetic and architectural concerns—required communication amongvariousprofessionals.Byprovidingallpartieswithaninformation-rich, 3Dexperience, SOLIDWORKS sparked the communication that brought the velarium back to Europe.

SDEI Ouest used SolidWorks design and simulation tools to design and build the first velarium since the fall of Rome at the Gallo-Roman stadium at Puy du Fou in Vendée, France.


Design, manufacture, and install a 5,500-square-meter canvas velarium atop the Puy du Fou arena in Vendée, France—an engineering project that has not been attempted since the fall of Rome.


Utilize SolidWorks Premium design and SolidWorks Simulation analysis solutions to design, engineer, and optimize the velarium’s 8,800 components.