Laura Galuppi

• Ph.D.
• Professor (Assistant) at University of Parma

Calculating the temperatures of windows of space stations in Low Earth Orbit (LEO) is crucial for ensuring their structural integrity. We present a comprehensive thermal analysis that considers direct solar radiation, Earth’s albedo effect, infrared radiation from the Earth and convective heat exchange with the internal environment. The thermal bal...

Calculating the temperatures of windows of space stations in Low Earth Orbit (LEO) is crucial for ensuring their structural integrity. We present a comprehensive thermal analysis that considers direct solar radiation, Earth’s albedo effect, infrared radiation from the Earth and convective heat exchange with the internal environment. The thermal bal...

The overall heating of satellites operating in low Earth orbit, essentially due to direct radiation from the Sun, terrestrial albedo, and planetary radiation, is well studied, but little is found specifically on transparent plates used for windowing spacecrafts. The most historic material of choice is fused silica; more recently, acrylic glass is b...

We propose a weak form of the transient heat equations for solid bodies, as a time-dependent spatial variation of the heat displacement vector field, whose time derivative is the heat flux. This develops the variational principle originally proposed by Biot, inasmuch Fourier's law is embedded as a holonomic constraint, while energy conservation res...

The stability of monolithic glass beams is reasonably well defined; as an elastic material it behaves in a similar manner to other elastic materials such as steel, for which there are many equations of different forms which give similar results. Special care is required for continuous restraint to the tension flange. Equations presented in Australia...

New generation thin, lightweight and damage-resistant glass, having impressively impact resistance and ability to be bent up to small radii, appears to be the optimal material for extremely deformable structural elements. Its structural use and design require an accurate evaluation of its mechanical properties. However, standard methods to test the...

The overall heating of satellites operating in low orbit, essentially due to direct radiation from the sun and terrestrial albedo, and the planetary radiation, is well studied, but little is found specifically on transparent plates used for windowing spacecrafts. The most historic material of choice is fused silica, as in the cupola of the Internat...

The stability of monolithic glass fins is reasonably well defined; as an elastic material it behaves in a similar manner to other elastic materials such as steel, for which there are many equations of different forms which give similar results. Special care is required for continuous restraint to the tension flange. Equations presented in Australia...

A critical issue in the design of structural glass elements in buildings is represented by the evaluation of thermally induced stresses and strains. For both climatic actions and fire, thermal stresses represent one of the main causes of premature failure, due to the high sensitivity of glass to temperature gradients. Thermal loads pose a severe sa...

Since the beginning of 2021, CEN/TS 19100 Design of Glass Structures has been available in its first three parts. The fourth part is expected soon. This Technical Specification of the European standards organisation CEN is as a pre-standard of a corresponding future Eurocode. These documents constitute the first ever comprehensive design code for t...

Prandtl’s membrane analogy for cylindrical bars under torsion is extended to beams with multi-material cross section of any geometry. It was demonstrated that the problem is governed by equations formally analogue to those describing the deformation of an inflated membrane, differently tensioned in the regions corresponding to the cross-section dom...

The thermal state in architectural glazed panes strongly depends on the properties of the components, on inclination, on solar radiation and, most of all, on projected shadows on the surface. The unevenness of temperature distribution in the pane, often referred to as “thermal shock”, can produce stresses leading to breakage. Determining the temper...

Breakages in architectural glazing are very often due to the thermal stress consequent to uneven heating of the glass pane, typically resulting from irregular shading. In thermal analyses to determine the insulating capacity of the fenestration, the temperature is conveniently assumed in-plane homogeneous, but a 3D approach is necessary to calculat...

The structural performance of laminated glass is strongly dependent on the shear coupling offered by the interlayer between the bounding layered and monolithic limits of the glass plies. The most common simplified design approach consists of defining the effective thickness, i.e., the thickness of a monolithic section with equivalent flexural secti...

The use of new generation thin, lightweight and damage-resistant glass, originally conceived for electronic displays, is moving its first steps in the built environment, in particular for adaptive and movable skins and façades. Its experimental characterization represents pearhaps one of the main open problems in glass research and engineering. Ind...

Cantilevered laminated glass installed in continuous U-profile base shoes are regularly constructed as structural glass guards, parapets, and windscreens. The structural performance of laminated glass is strongly dependent on the shear coupling offered by the interlayer, between the bounding layered and monolithic limits of the glass lites. The mos...

A critical issue in the structural design of glazed surfaces is the evaluation of the strain consequent to temperature variations due to environmental actions such as solar radiation, which represents one of the main causes of breakage. In the practice, approximate solutions are used, where the temperature profile across the glass thickness is cons...

>>> https://www.mdpi.com/journal/buildings/special_issues/women_buildings Dear Colleagues, It is well known that in the areas of STEM (Science, Technology, Engineering, and Mathematics), the bias of gender balance is particularly exaggerated. The number of male researchers working in STEM is much larger than that of women, and this is consistent...

Insulated Glazed Units (IGUs) are composite elements formed by two or more glass panes held together by structural edge seals, entrapping a gas for thermal and acoustic insulation. There is a wealth of evidence that they are prone to cracking due to an uneven temperature distribution within each glass pane, caused in particular by solar radiation,...

The proper assessment of shear coupling is necessary for the evaluation of laminated glass performance between the bounding layered and monolithic limits. The most common simplified design approach consists in defining the effective thickness, i.e., the thickness of a monolithic section with equivalent flexural properties. Cantilevered laminated gl...

The precise assessment of the temperature distribution on glass panes, whether they are single windows or façade components, is of paramount importance for the safety and durability of building skins, because many experienced breakages are due to the thermal stress resulting from solar radiation. Here, an enhanced engineered method for the calculat...

This paper proposes a concise concept for quantifying the shear/torsional stiffness of the laminated glass beams experimentally by introducing the Equivalent-Sectional Shear Modulus (ESSM), that is directly measured from the torque and sectional-rotation correlation with the torsion test and tailor-made photogrammetry technique. The advantage of th...

This paper proposes a concise concept for quantifying the shear/torsional stiffness of the laminated glass beams experimentally by introducing the Equivalent-Sectional Shear Modulus (ESSM), that is directly measured from the torque and sectional-rotation correlation with the torsion test and tailor-made photogrammetry technique. The advantage of th...

Laminated glass is a composite made of elastic glass layers sandwiching thin viscoelastic polymeric interlayers. There are several types of polymers, traditionally modelled as linear viscoelastic materials using a Prony’s series of units in the Maxwell-Wiechert arrangement. We show that one single element with fractional viscoelastic properties (tw...

The structural response of Double Glazing Units (DGUs), composed by two glass panes held together by structural edge seals, entrapping a gas for thermal and acoustic insulation, is governed by the load sharing between the glass elements, due to a complex interaction with the gas in the interpane space. Various methods are proposed by standards to e...

Insulating Glazing Units (IGUs) are glass panes held together by structural edge seals, entrapping a gas for thermal and acoustic insulation. The bending of one pane induces pressure variations in the cavities, which produce the load sharing through the gas with the other panes. Under mild hypotheses, the whole IGU behaves as a linear elastic syste...

Double Glazed Units (DGUs) consist of two glass panes held together by structural edge seals. Calculation methods for DGUs consider that actions applied on one pane develop effects in all the panes, due to the coupling from the entrapped gas. Various methods have been proposed in standards to evaluate this load sharing, which depends upon the stiff...

A conjugate beam analogy is here proposed to evaluate the shear coupling in three-layered laminates formed by two external elastic plies bonded by a compliant interlayer. Based on the formal analogy of the governing equations, the method allows the evaluation of the shear coupling in the external plies by studying the response of a monolithic conju...

Because of their characteristic high slenderness ratios, laminated glass elements are frequently subjected to buckling phenomena. Here, simple analytical formulae for the evaluation of the effective thickness for the compressive buckling verification of laminated glass beams are proposed, based on the Enhanced Effective Thickness model, widely used...

Double Glazed Units (DGU) consist of two glass panes held together by structural edge seals, entrapping a gas for thermal and acoustic insulation. The interaction between panes and gas is structurally beneficial because it permits the sharing on both panes of applied loads. Here, a tailored use of the Reciprocal Work Theorem by Betti provides an an...

In the post-breakage phase, laminated glass (LG) can maintain a residual load-bearing capacity due to the tension stiffening of the polymer through the adhesion with the shards, but the determination of the overall post-breakage stiffness presents formidable difficulties. A simple model is here proposed for the in-plane response of broken thermally...

Laminated glass, composed by glass plies bonded by polymeric interlayers, is used for structural purposes thanks to its safe post-glass-breakage response. When glass breaks, the shards remain attached to the interlayer, imparting to the damaged element a residual load-bearing capacity, influenced by the tension stiffening of the polymer through the...

We analyze the pure bending state, preliminarily considering the pure traction problem, for a fiber with circular cross-section composed by monodispersed Nano Tube (NT) segments, whose length is much lower than the length of the fiber, arranged in a cross-sectional square lattice, possibly inclined with respect to the bending plane. The proposed mo...

Cantilevered laminated glass balustrades supported by bearing in continuous base shoes are among the most ordinary applications of structural glass. The performance of laminated glass is commonly approximated with the Effective Thickness Method by Bennison, adapted from composite sandwich theory by Wӧlfel for a simply-supported beam under uniformly...

New generation thin, lightweight and damage-resistant glass seems to be the optimal material for extremely deformable structural elements for façades and building skins. Here, an innovative concept is proposed, based on the use of cold-twisted square elements and on the exploitation of their buckling phenomenon, causing the shape modification from...

Prandtl's membrane analogy for the torsion problem of prismatic homogeneous bars is extended to multi-material cross sections. The linear elastic problem is governed by the same equations describing the deformation of an inflated membrane, differently tensioned in regions that correspond to the domains hosting different materials in the bar cross s...

The use of new generation thin, lightweight and damageresistant glass, originally conceived for electronic displays, is being very recently proposed for structural applications, in particular for adaptive and movable skins and façades. This paper explores this concept and presents a study on the structural use of thin glass in greenhouses for prote...

Since their discovery, carbon nanotubes (CNTs) have been widely perceived as a very promising material, because of their unique physical and electrical properties. CNTs have also remarkable properties and qualities as structural materials, such as stiffness, toughness and strength, leading to a wealth of applications exploiting them, including adva...

Any reliable use of glass for structural purposes cannot neglect that its breakage may be provoked by imponderable events, like impacts at critical spots or thermal shocks. Laminated glass, composed by glass plies sandwiching polymeric interlayer sheets, is used in architectural application thanks to its safe post-glass breakage response. When glas...

The goal of the present study is to evaluate the equivalent stiffness of a damaged laminate. The considered model problem is that of a three-layer laminate composed by external stiff plies sandwiching an elastic “soft” core, with external layers cracked according to a regular pattern, with the resulting fragments partially delaminated from the inne...

Architectural trends move towards free-form building envelopes. Curved transparent panels can be obtained via “cold-bending”, by elastically constraining laminated glass in the desired curved shape. Due to the interlayer viscosity, the element exhibits a stress relaxation from the instant in which it is positioned. Another possibility is “cold-lami...

laminated glass maintains significant stiffness and strength even when all glass plies are broken. A homogenized approach is presented that fits the case of broken tempered glass, characterized by small shards approximately of the same size. The tension stiffening is evaluated as a stress perturbation, determined within a class of shape functions t...

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We extend, to the case of equibiaxial states of stress, the variational approach originally proposed by Hashin for the analysis of cracked three-layer laminates under uniaxial tensile loading. The type of damage considered here is complementary to that analyzed by Hashin, in the fact that the external plies of the laminate, rather than the inner la...

Laminated glass, a composite made by bonding glass plies with polymeric interlayers, can maintain a significant load bearing capacity even when glass is broken, because of the adhesion of the glass shards to the interlayer. The post-breakage response is strongly associated with the safety performance, but it is not as well studied as the pre-glass...

The stiffness and strength of a composite structure formed by a slab and an underlying beam made of different materials strongly depends on the shear coupling at their interface, which in general is not perfect because of the compliance of the shear connectors. The proposed approach interprets the effects of this partial interaction by establishing...

Approximate methods for calculating Laminated Glass (LG), a composite where thin polymeric layers are sandwiched by glass plies, are very useful in the design practice. The most common approach relies upon the definition of the effective thickness, i.e., the thickness of a glass monolith that, under the same boundary and load conditions, presents t...

Cold-lamination-bending (CLB) of glass consists, first, in constraining the unbonded glass-interlayer package in the desired curved shape and, second, in performing the lamination process in autoclave. Releasing the laminate, the curvature is only partially maintained through the interlayer bond, due to an initial spring-back followed by the relaxa...

An analytical study is presented for the bent-lamination of curved layered beams, a process consisting in gluing the constituent plies together after they have been elastically bent against a constraining negative mould. Possible applications range from glued laminated timber manufacturing, to cold-lamination-bending of structural glass. After remo...

In recent years, sandwich structures made by the composition of elastic beams bonded by adhesive layers have been increasingly used in civil, aerospace and automobile constructions. An interesting technique to obtain curved elements is bent-lamination, consisting in gluing the constituent plies together after they have been elastically bent against...

A method of solution that extends to the case of curved laminated structures the traditional approach developed by Newmark et al. for straight beams is presented. The method is specialized to curved laminated glass, a composite formed by two external glass layers that sandwich a very thin polymeric interlayer. The effect of curvature on the shear c...

The paradigmatic example of a twisted square plate is here considered. An equivalent partition of the plate in a grid of beams à la Grashof is found such that, as the number of beams tends to infinity, the grid exhibits the same deflection of the plate. This scheme is used to interpret, through the distinction between Euler–Bernoulli and Timoshenko...

Cold-bending of laminated glass panels, by forcing their contact with a constraining frame, is a promising technique for free-form glazed surfaces. Their static state varies in time due to the viscosity of the polymeric interlayer, which causes the decay of the shear-coupling of the constituent glass plies. The direct problem consists in calculatin...

We consider a composite package formed by two curved external Euler-Bernoulli beams, which sandwich an elastic core with negligible bending strength but providing the shear coupling of the external layers. This coupling considerably affects the gross response of the composite structure. There is an extensive literature on straight sandwich beams of...

We consider a composite package formed by two curved external Euler-Bernoulli beams, which sandwich an elastic core with negligible bending strength but providing the shear coupling of the external layers. This coupling considerably affects the gross response of the composite structure. There is an extensive literature on straight sandwich beams of...

A method of solution that extends to the case of curved laminated structures the traditional approach developed by Newmark et al. for straight beams is presented. The method is specialized to curved laminated glass, a composite formed by two external glass layers that sandwich a very thin polymeric interlayer. The effect of curvature on the shear c...

Double curved anticlastic glazed surfaces are widely used for free-form façades and roofs of modern buildings. An effective technique consists in cold bending rectangular glass plies by twisting them with forces applied at the corners. The linear Kirchhoff-Love theory predicts that the deformed shape is a hyperbolic paraboloid, which preserves the...

Sintering of precompacted metallic and ceramic micro and nanopowders is a complex problem influenced by several factors. We quantify the influence of both local capillary stresses acting at the surface of one pore or particle (usually referred to as Laplace pressure) and the gas pressure in pores during sintering of precompacted metallic (micro/nan...

A promising technique to obtain free-form curved glazing consists in cold-bending glass panels by forcing them in the desired position. When the glass is laminated, the static state of the forced panel varies in time because of the viscoelasticity of the polymeric interlayer, which causes the decay of the shear-coupling of the constituent glass pli...

A three-layered structure is composed by two external elastic beams that sandwich a viscoelastic core providing their shear coupling. The time-dependent bending of a simply-supported composite-beam of this type, axially-compressed and with an initial sag, are studied assuming a Maxwell–Wierchert constitutive model of viscoelasticity accounting for...

Guidance for European structural design of glass components Support to the implementation, harmonization and further development of the Eurocodes This JRC Scientific and Policy Report is a pre-normative document that represents the basis of a new Eurocode on the design of structural glass. It was developed by CEN/TC 250 WG 3 and it presents the av...

Laminated glass is a layered sandwich structures composed of elastic glass plies bonded by viscoelastic polymeric interlayers, which produce the mechanical shear-coupling of the plies under flexural loads. Here, we analytically solve the time-dependent problem of a simply-supported three-layered sandwich-beam with linear-viscoelastic interlayer und...

Laminated glass is a layered sandwich structures composed of elastic glass plies bonded by viscoelastic polymeric interlayers, which produce the mechanical shear-coupling of the plies under flexural loads. Here, we analytically solve the time-dependent problem of a simply-supported three-layered sandwich-beam with linear-viscoelastic interlayer und...

Due to deformability of the polymeric interlayer, stiffness and strength of laminated glass are usually less than those corresponding to a monolith with same total thickness. A practical design tool consists in the definition of the deflection- and stress-effective thickness, i.e., the thickness of an equivalent monolithic glass that would correspo...

We analytically solve the time-dependent problem of a simply-supported laminated beam, composed of two elastic layers connected by a viscoelastic interlayer, whose response is modeled by a Prony’s series of Maxwell elements. This case applies in particular to laminated glass, a composite made of glass plies bonded together by polymeric films. A pra...

The flexural performance of laminated glass, a composite of two or more glass plies bonded together by polymeric interlayers, depends upon shear coupling between the glass components through the polymer. This effect is usually taken into account, in the design practice, through the definition of the effective thickness, i.e., the thickness of a mon...

The deformability of the interlayer does not provide a perfect shear transfer between the glass plies, so that flexural response of laminated glass is somehow intermediate between that of a monolith and that of free-sliding plies. In the design practice, this effect is usually taken into account through the definition of the Effective Thickness (ET...