This article deals with the dynamic response of thin circular clamped GLARE fiber—metal laminates subjected to low velocity impact by a lateral hemispherical impactor. Using a spring-mass model, the differential equations of motion corresponding to loading and unloading stages of impact are derived and solved numerically. Internal damage due to delamination is taken into account. Previously published analytical formulas^1,2 concerning the indentation of circular GLARE plates are used during the loading stages of impact. In this study, an equation for the unloading path is derived and used during the unloading impact stage. The load—time, position—time, velocity—time, and kinetic energy—time history responses are calculated. In this regard, the position where delamination occurs, the maximum plate deformation and the position where the impact load becomes zero are predicted. Also, the maximum impact load and the total impact duration are determined. The derived differential equations of motion are applied for GLARE 4-3/2 and GLARE 5-2/1 circular plates subjected to low velocity impact. The predicted load—time history response is compared with published experimental data and a good agreement is found. No other solution of this problem is known to the authors.

In this article, the elastic buckling response of rectangular simply supported and clamped fiber-metal laminates (FMLs) subjected to uniaxial compressive loading is investigated using the finite element method and eigenvalue buckling analysis. Using validated finite element method (FEM) models, the buckling coefficient-aspect ratio diagrams and the mode shapes of nine GLARE grades are obtained and studied along with the diagrams and the mode shapes of three unidirectional glass-epoxy composites and monolithic 2024-T3 aluminum. It is found that the critical average buckling stress and the buckling load of the materials increases for increasing metal volume fraction, when the plate aspect ratio is greater than 1.5. The rule of mixtures is evaluated and found to be a simple method to estimate approximately the average critical buckling stress of the GLARE plates. An approximate formula is derived for the estimation of the critical buckling coefficient of the GLARE plates using the buckling coefficients of their constituents. The applicability of the results to thermoplastic-based FMLs is discussed.

This article deals with the dynamic response of thin circular clamped GLARE (GLAss REinforced) fiber-metal laminates subjected to low-velocity impact by a lateral hemispherical impactor, striking at the center with constant kinetic energy. The laminates have equal total thickness and consist of GLARE 2A-3/2-0.4, GLARE 2A-4/3-0.238, GLARE 3-3/2-0.4, GLARE 4-3/2-0.317, and GLARE 5-3/2-0.233 standard grades. Three different plate diameters are considered for each GLARE grade. Their dynamic response is predicted by solving previously published differential equations of motion corresponding to a spring-mass modeling of the impact phenomenon. The obtained results are analyzed and compared in order to understand and evaluate the performance of the examined material grades along with the effect of different plate radius. With reference to the radius variation, it is found that it affects substantially the overall impact behavior of a GLARE plate. As far as the examined material grades are concerned, similarities and differences related with their impact behavior are recorded and a comparative evaluation is implemented. Characteristic variables associated with the low-velocity impact response of fiber-metal laminates are discussed and pertinent design recommendations are proposed.

In this paper, analytical expressions are derived and a finite element modelling procedure is proposed in order to predict the static load-indentation curves of circular GLARE fibre-metal laminates during loading and unloading by a hemispherical indentor. Analytical formulas have been recently published for the static indentation of circular GLARE plates which are now used during the loading stage. Here, considering that aluminum layers are in a state of membrane yield and employing energy balance during unloading, the unloading path is determined. Using this unloading path, an algebraic equation is derived and solved for calculating the permanent dent depth of the GLARE plate after the indentor's withdrawal. ANSYS software is used and a non-linear analysis is employed with geometric and material non-linearities for FEM calculations. The derived formulas and the proposed finite element modelling procedure are applied to GLARE 2-2/1-0.3 and to GLARE 3-3/2-0.4 circular plates. The analytical results are compared with corresponding FEM results and a good agreement is found. The analytically calculated permanent dent depth is within 6 % for the GLARE 2 plate, and within 7 % for the GLARE 3 plate, of the corresponding numerically calculated result. No other solution of this problem is known to the authors.

This article deals with the response of GLARE (GLAss REinforced) fiber–metal laminates subjected to frictional oblique indentation. The indentation response is initially predicted using ANSYS software and a three-dimensional analysis with geometric and material nonlinearities. The classical Coulomb friction model is employed to simulate friction between the contacting surfaces. Then, analytical formulae are derived to predict the GLARE plate indentation load and strain energy as a function of the indentor’s displacement, the friction coefficient, and the indentation direction. These formulae are applied successfully for the GLARE plates with various diameters and indentation directions. The analytical results agree very well with the corresponding finite element analysis results.