Xavier Tellier

Urban Canopee

We address the computational design of architectural structures which are based on a grid of intersecting beams that are aligned with the parameter lines of a quad mesh. While previous work mainly put a planarity constraint onto the faces of the mesh, we focus on the planarity of long-range supporting beams which follow selected polylines in the un...

The design of curved structural building envelopes such as gridshells or cable-net roofs is challenging as it requires to account for a wide variety of constraints. In particular, the chosen shape must be mechanically efficient, fabricable, and fit the site geometry. This article shows how a family of surfaces, called isotropic Linear Weingarten (i...

In this paper we investigate geometric properties and modeling capabilities of quad meshes with planar faces whose mesh polylines enjoy the additional property of being contained in a single plane. This planarity is a major benefit in architectural design and building construction: if a structural element is contained in a plane, it can be manufact...

This two-part article introduces the concept of alignable nets, forms of elastic gridshells which may be deployed from a compact bundle state, thus offering advantages for transportation and prefabrication. Whereas the first part focused on analytical solutions, this second tackles their numerical form-finding. A design workflow is introduced to de...

Elastic gridshells (EGS) offer a cost-effective and rapid way to construct lightweight structures. This paper focuses on bundlable EGS, gridshells which may be deployed from a compact slender state, thus allowing for off-site fabrication. Some bundlable EGS have the additional property of being self-shaping, an aspect that simplifies considerably t...

The design and construction of doubly-curved structures often reveals to be challenging and can result in complex manufacturing and assembly. A recent strategy to tackle this difficulty consists in exploiting the connection between discrete differential geometry and constructive properties to identify curve networks with good fabrication or mechani...

Elastic gridshells offer a cost-effective and rapid way to construct lightweight structures. They are commonly composed of regular grids, in which the distance between two adjacent connections is constant. This guarantees that the structure can be assembled at ground level in a stressless configuration, but imposes a strong geometrical constraint o...

Funicular structures can resist a given load with pure axial forces and therefore tend to use material very efficiently. One main challenge in their design is form finding, which often requires advanced numerical methods. In this article, we show analytically that a very common family of curves, conics, is funicular for a particular load case: a un...

Isotropic Linear-Weingarten surfaces are a rich family of shapes, which contains some popular architectural surfaces such as paraboloids. We prove that these shapes are funicular for a uniform vertical load, and that the stress lines then form a conjugate net. This allows to design structures with planar facets, in which the edges have an optimal m...

Curved envelope structural building envelopes have been quite popular in architecture in the past decades, and pose many challenges in their design, manufacturing and planning. In gridshells, a popular structural morphology for curved structure, designers will often strive to orient beams such that their top face is parallel to the envelope surface...

The design of envelopes with complex geometries often leads to construction challenges. To overcome these difficulties, resorting to discrete differential geometry proved successful by establishing close links between mesh properties and the existence of good fabrication, assembling and mechanical properties. In this paper, the design of a special...

Curved structural envelopes have been popular in architecture in the past decades. Their main limitation is their high cost, which is due in particular to the manufacturing complexity induced by curvature. This article introduces Caravel meshes, a new family of meshes that offers geometrical properties allowing a significant reduction of fabricatio...

Designing a curved architectural envelope is a challenging task, as it requires a balance between structural efficiency, fabricability, and architectural requirements. In this article, we introduce a new conceptual design tool: Linear‐Weingarten membranes, with boundaries either simply supported or realized as funicular cables or arches. We present...

Curved structural envelopes combine mechanical efficiency, architectural potential and a wide design space to fulfill functional and environment goals. The main barrier to their use is that curvature complicates manufacturing, assembly and design, such that cost and construction time are usually significantly higher than for parallelepipedic struct...

(Published in SN Applied Sciences Journal, full text available at: https://rdcu.be/b3k70) The fabrication of a freeform structural envelope is usually a highly complex task. The costliest aspect is often the connections between the constitutive parts. The Caravel heX-Mesh Pavilion is a prototype that demonstrates a new rationalization strategy. It...

The fabrication of a freeform structural envelope is usually a highly complex task. The costliest aspect is often the connections between the constitutive parts. X-Mesh is a pavilion that demonstrates a new rationalization strategy. Its structure, composed of a hexagonal grid of beams and cladding panels, is based on a geometry that rationalizes co...

The shape of a complex freeform architectural envelope is usually generated by methods such as NURBS that offer a great design freedom, but that do not take into account fabricability. This often leads to higher than expected building costs. In this article, we present how a forgotten family of surfaces-namely, surfaces with planar curvature lines-...

Designing freeform architectural envelopes is a challenging task, as it requires a balance be-tween structural efficiency, fabricability and architectural requirements. In this article, we present a novel numerical form-finding method based on the generation of the so-called Linear Weingarten surfaces. The method allows to build these surfaces on a...

In this paper, we propose a method to generate circular and conical meshes with planar lines in both directions. The method is based on the discretization of the Gauss map of surfaces with planar curvatures lines. It allows generation of meshes in real-time via two planar guide curves. The resulting meshes can be used as a geometric base to build g...

Les structures à double courbure telles que les membranes tendues et les gridshells allient performance mécanique et élégance architecturale. La recherche de forme de ces structures peut être complexe, et fait l'objet d'un arbitrage entre efficacité mécanique, facilité de fabrication et esthétique. Dans cet article, nous proposons une nouvelle méth...

Constant mean curvature surfaces (CMCs) have many interesting properties for use as a form for doubly curved structural envelopes. The discretization of these surfaces has been a focus of research amongst the discrete differential geometry community. Many of the proposed discretizations have remarkable properties for envelope rationalization purpos...

This paper presents the design and fabrication of an innovative structure, spanning 6.5m with a structural thickness of 12cm. The structural system derives from nexorades, also called reciprocal frames by some authors, obtained by a novel form-finding method based upon translation of the edges. It also allows for the covering with planar facets if...

In double-curvature gridshells covered with rigid flat panels, panels cannot lay flat on the top surface of beams. In many cases, costly elements need to be inserted in-between to insure a proper beam-panel connection. Precedent research on the geometric rationalization of gridshells has mostly focused on minimizing cladding panel curvature, simpli...

Concrete tilt-up building is a prevalent construction technique used for industrial and commercial applications in North America. This construction technique offers many significant advantages over conventional cast-in-place construction. This includes the reduction in construction time and the amount of formworks. Despite the large array of buildi...