Finite element parametric study

The repair laminate was assumed to be reinforced with a bidirectional carbon fibre woven fabric with equal number of tows by weight in the weft and warp direction. The matrix was assumed to be epoxy. The laminate properties used for the FEA simulation were calculated using mle-of-mixtures (Daniel and Ishai, 1995), assuming a fibre volume fraction of 40%. The laminate elastic properties are given in Table 11.2. To calculate the repair thickness, the composite allowable strain (sc) was limited to 0.3%, selected as a number in between the two extremes (0.25% and 0.40%) proposed by ASME PCC-2 and also equal to the allowable strain for a class 2 repair with a 10 year lifetime. 

Different design scenarios that were considered in this smdy are presented in Table 11.3. The erosion/defect was assumed to be circumferential with a constant circumferential depth and the wall thinning was considered in the range of 30—80% in increments of 10%. The maximum allowable internal pressure for the corroded pipe was calculated based on ASME B31.4 considering the remaining wall thickness of the pipe. In the study, the live pressure varied from 0 to 100% of the maximum allowable live pressure in steps of 25%. The minimum laminate thickness for each repair situation was calculated using Eqn (11.1) (based on ISO 24,817 and ASME PCC-2) and Eqn (11.10), as given in Table 11.3. 

Defect depth % Maximum allowable internal pressure in damaged pipe t un (mm)  

Fignre 11.1 (a) FEA mesh and (b) material orientation for repair laminate. 

Rehabilitation of Kpelines Using Fiber-reinforced Polymer (FRP) Composites 

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M.F. Horstemeyer et al Using a micromechanical finite element parametric study to motivate a phenomenological macroscale model for void/crack nucleation in aluminum with a hard second phase. Mech. Matls. 35, 675-687 (2003)... 

Yetham, L. A., Godfreg, P. M., Chinn, P. B. Materials for Motorcycle Crash Helmets a Finite Element Parametric Study. Plastics. Rubber and Composite Processing and Applications 1994 22 215-21. 

In the previous finite element parametric study of cracked steel plate with CFRP patching, the material properties of the 1.2-mm-thick CFRP plate (Sika, 2003) were assigned for the CFRP patching. In order to compare results of the plate model and the tube model, the same material properties of the CFRP plate were assigned for... 

Cartie D.D.R and Partridge I.K., (2001) A finite element tool for parametric studies of delamination in Z-pinned laminates . Proceedings of DFC6, Manchester Conference Centre, Manchester, UK, pp. 49-55, loM communications. 

The calculated stress values were compared with those measured experimentally either by X-ray diffraction on graded WC/Co specimens or by deflection measurements during electrochemical removal of subsequent layers for graded CuNi samples. The comparison with experimental methods showed good agreement, thus validating the results obtained by the parametric finite element study. 

A select set of different simulations (Figs. 11.26 and 11.27) were then performed in a parametric study of different seal and connection geometries. The predictions from the finite element simulations were validated further by a few select full-scale experiments on real pipeline parts. 

Khalil, T. B., Hubbard, R. P. Parametric study of head response by finite element modeUing. Journal of Biomechanics, 1977 10(2) 119-32. 

Recent theoretical studies have become much more complex. New computer-assisted techniques permit the use of finite-element matrix-theory type approaches. The effects of important variables are being determined by parametric studies. More complex joints are also being studied. New adherend materials, including advanced filamentary composites, are also being evaluated. The elastic, low-deflection, constant temperature behavior of scarf and stepped-lap joints has been replaced by elastic-plastic, large-deflection behavior, combined with thermal expansion differences, or curing shrinkage-induced residual stresses. 

Parametric studies on two kinds of electrodes for circle-shaped diaphragms with a radius of 10 mm were conducted with the material properties and thicknesses shown in Table 9.2 [3]. The material properties E and dsj of the IPMC in Li" form were determined thorough the equivalent bimorph beam model [28]. The elastic modulus of Nafion in Li form and Poisson s ratios were obtained from literature [32, 33]. Figure 9.10 shows the shape of the two electrodes in a one-quarter finite element model of diaphragms. Figure 9.10a is the circle-shaped electrode and 9.10b is the ring-shaped electrode. 

M. Osman and R. A. Sauer, A parametric study of the hydrophobicity of rough surfaces based on finite element computations. Colloids Surfaces, A 461,119-125 (2014). 

As an application of the theory discussed earlier, the crash responses of aircraft occupant/stnicture will be presented. To improve aircraft crash safety, conditions critical to occupants survival during a crash must be known. In view of the importance of this problem, studies of post-crash dynamic behavior of victims are necessary in order to reduce severe injuries. In this study, crash dynamics program SOM-LA/TA (Seat Occupant Model - Light Aircraft / Transport Aircraft) was used (13,14]. Modifications were performed in the program for reconstruction of an occupant s head impact with the interior walls or bulkhead. A viscoelastic-type contact force model of exponential form was used to represent the compliance characteristics of the bulkhead. Correlated studies of analytical simulations with impact sled test results were accomplished. A parametric study of the coefficients in the contact force model was then performed in order to obtain the correlations between the coefficients and the Head Injury Criteria. A measure of optimal values for the bulkhead compliance and displacement requirements was thus achieved in order to keep the possibility of a head injury as little as possible. This information could in turn be usm in the selection of suitable materials for the bulkhead, instrument panel, or interior walls of an aircraft. Before introducing the contact force model representing the occupant head impacting the interior walls, descriptions of impact sled test facilities, multibody dynamics and finite element models of the occupant/seat/restraint system, duplication of experiments, and measure of head injury are provided. 

G. H., and Armstrong, C.G. (2004) A non-isothermal finite element model for injection stretch-blow molding of PET bottles with parametric studies. Polym. Eng. Sci., 44, 1379-1390. 

Often, there may not be sufficient material test data to calibrate all the material parameters in a finite element model. In such cases, a sensitivity analysis is required to determine the sensitivity of the numerical results to the values of parameters that cannot be determined from material test data. A parametric study by Stavridis and Shing (2010) with finite element models has indicated that the shear strength parameters for mortar joints are most influential on the load-displacement response of an infilled frame. 

In order to assess the effectiveness of such an impact mitigation measure, proper numerical simulations and parametric studies are needed, considering various types and configurations of structures under different dynamic excitations. Nevertheless, the behavior of rubber shock absorbers under impact loading must be sufficiently well modeled. Undoubtedly, the most precise modeling can be achieved with the development of a detailed finite element model using special elements and material laws to... 

Amorosi A, Boldini D, Elia G (2010) Parametric study on seismic ground response by finite element modelling. Comput Geotech 37(4) 515-528... 

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