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Sandwich panel

About: Sandwich panel is a research topic. Over the lifetime, 4665 publications have been published within this topic receiving 49812 citations.


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Journal ArticleDOI
TL;DR: A mathematical model based on a multi-scale asymptotic technique for the dynamic description of honeycomb structures is presented in this paper, which is used to evaluate an equivalent orthotropic model of the honeycomb.
Abstract: In this paper a mathematical model based on a multi-scale asymptotic technique for the dynamic description of honeycomb structures is presented. The technique is used to evaluate an equivalent orthotropic model of the honeycomb. The derivation is based on an asymptotic analysis for periodic structures developed by Bensoussan, Lions and Papanicolaou. The method is totally general; in fact, it is applied to Cauchy’s partial differential equations that describes the dynamics of an elastic material. Elastic and density characteristics are determined in terms of the cell geometry and material of the honeycomb. A numerical validation is carried out by using a finite-element modeling (FEM) numerical simulation.

18 citations

Journal ArticleDOI
TL;DR: In this paper, a theoretical approach to damage-tolerant structural design has been proposed based on a probabilistic characterization of relative structural safety, which is defined, for a single inspection event, as the compliment of the probability that a single flaw size larger than the critical flaw size for residual strength of the structure exists and that the flaw will not be detected.
Abstract: A theoretical approach to damage-tolerant structural design has been proposed based on a probabilistic characterization of relative structural safety. The equations necessary to quantify damage-tolerant structural safety are developed, and their use in the design of a generic composite sandwich panel are demonstrated. Structural safety is identified by the term level of safety, which is defined, for a single inspection event, as the compliment of the probability that a single flaw size larger than the critical flaw size for residual strength of the structure exists and that the flaw will not be detected. The equations derived from this definition incorporate a probabilistic treatment of damage sizes and inspection capabilities. Utilizing damage size data from existing composite aircraft components along with the level of safety, formulas, design charts for residual strength vs safety of a generic composite sandwich panel were constructed. An example design problem is presented that demonstrates the sensitivity of the facesheet thickness sizing parameters to the relative safety of the design. Bayesian statistical techniques are also incorporated to enable the subsequent use of service inspection data to reduce uncertainty in the damage size distributions and to update the structural level of safety value as service experience is acquired.

18 citations

Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the blast performance of corrugated core steel sandwich structures with foam fillings and found that soft/hard foam core arrangement strategies are most effective in mitigating blast and give the smallest back face displacements under shock loading.
Abstract: An experimental/numerical study was conducted to evaluate the blast performance of corrugated core steel sandwich structures with foam fillings. The core was preferentially filled with foam with the objective of creating a structure with superiror blast mitigation properties. Different core filling strategies used in the study are shown in Fig. 1(a). Core topologies were arranged as soft/hard, soft/hard/soft, hard/soft/hard and hard/soft as multilayers towards the blast loading direction. The experimental set-up is shown in figure 1(b). The blast loading was imparted using a shock tube facility and the resulting dynamic event was photographed using a high speed camera. Numerical analyses were performed using ABAQUS/EXPLICIT finite element software. The loading profile and material discretization used for numerical simulation are shown in Fig. 2. The material properties of the face sheets and the corrugations were used for standard low carbon steel material. General purpose humidity cured polyurethane foam was used for filling corrugations. The Johnson Cook material model with strain hardening and Ogden was used in Abaqus as material model for low carbon steel and PU foam, respectively. Numerical models were verified by using deflection data from high speed camera measurements. The experimental and numerical results shown in Fig. 3 and Fig. 4, respectively, illustrate that Soft/hard foam core arrangement strategies are most effective in mitigating blast and give the smallest back face displacements under shock loading.

18 citations

Journal ArticleDOI
TL;DR: In this article, the authors used a solitary wave-based diagnostic scheme for the detection of core-skin disbonds in composite sandwich structures comprising of carbon-fiber/epoxy skins and a Nomex™ honeycomb core.

18 citations

Journal ArticleDOI
TL;DR: In this paper, the core shear stresses are determined from equilibrium of the face sheets independent of core yield, and an algorithm is constructed for determining shear deflection. But when the bilinear stress-strain behavior approaches the perfectly plastic core, the classical sandwich theory assumptions begin to break down and the face sheet now carries an appreciable part of the shear load.
Abstract: Sandwich panels can failin a variety of ways. In the present article one type of failure is investigated and modeled that has a number of important applications, e.g., marine hulls. Here core yielding is assumed to initiate and grow in the sandwich panel while the face sheets remain bonded, unbuckled, and in the elastic range. For elastic face sheets, the core shear stresses can be determined from equilibrium of the face sheets independent of core yield. Core shear strains can then be found from the stress-strain curve and an algorithm is constructed for determining shear deflection. Bending deflection is found from the elastic solution. This approach works well except when the bilinear stress-strain behavior approaches the perfectly plastic core. With the aid of a detailed finite-element solution, it is shown that the classical sandwich theory assumptions begin to break down and that the face sheets now carry an appreciable part of the shear load. This effect is shown in detail for four-point beam bendin...

18 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202384
2022217
2021244
2020280
2019264
2018252