A carregar...
Projeto de investigação
Centre for Mechanical Technology and Automation
Financiador
Autores
Publicações
Hyperbolic models to represent the effect of mechanical damage and abrasion on the short-term tensile response of a geocomposite
Publication . Lombardi, G.; Pinho-Lopes, Margarida; Paula, António Miguel; Bastos, António
The objective of this study was to analyse the short-term tensile response of a geocomposite (a geotextile and a geogrid overlapped) and apply hyperbolic models to describe its load-strain tensile curves. Data from specimens submitted to mechanical damage, abrasion, and mechanical damaged followed by abrasion were analysed. Reduction factors were proposed by comparing data from damaged specimens with those from undamaged specimens. The experimental results were compared with those fitted by the constitutive models to validate the model. The constitutive models demonstrated good fitting capacity. For any mechanical condition, the model parameters could be estimated by relating the experimental tensile properties of the geocomposite with adjustment coefficients, which allowed for describing the tensile load-strain curves with good accuracy. The reduction factors for the specimens subjected to mechanical damage followed by abrasion were lower than the values which would be obtained if the damages were considered individually.
A simple 3D orthotropic model for the tensile response of geogrids: in-isolation and soil–geogrid interaction applications
Publication . Paiva, Lucas; Pinho-Lopes, Margarida; Valente, Robertt; Paula, António Miguel
The short-term tensile response is one of the key aspects in designing geogrid-reinforced soil structures. In this paper a simple data-driven 3D orthotropic model for the short-term tensile response is proposed. The Hill48 yield model is chosen to represent the orthotropic behaviour of the geogrid, and a procedure to obtain the necessary parameters, from simple tensile test data, is presented. The model is then implemented in ABAQUS, and validated against a realistic problem where the geogrid is embedded in soil. The influence of the orthotropy (against isotropy) on both the reinforcement and the overall soil-geogrid structure is evaluated. The results show that the orthotropic model can accurately predict the tensile response of the geogrid in different directions, with the orthotropy having a significant influence on the reinforcement and the overall structural response, especially in highly orthotropic materials. The study further examined stress redistribution capabilities in geogrids with notches, revealing enhanced stabilization performance using the orthotropic model. Parametric tests indicated that traditional isotropic assumptions might underpredict or overpredict reinforcement performance, emphasizing the advantages for accurate orthotropic characterization. The proposed 3D framework provides a robust, straightforward method for evaluating and optimizing geogrid designs, enabling better prediction of reinforced soil behaviour in geotechnical applications.
A constitutive model for describing the tensile response of woven polyethylene terephthalate geogrids after damage
Publication . Lombardi, Giovani; Pinho-Lopes, Margarida; Paula, António Miguel; Pereira, António
A constitutive model was used to describe the tensile response of two woven Polyethylene Terephthalate (PET) geogrids, before and after mechanical damage. The model parameters of undamaged and damaged specimens were estimated via numerical regressions of test results. For each sample, the experimental and fitted tensile strengths were statistically compared using hypothesis tests. For each geogrid, tensile load-strain curves of damaged samples were drawn by applying scaling factors to the plot of the undamaged sample. The curve fittings resulted in high R-2 values for undamaged and damaged specimens of the geogrids. For most samples, there was no significant mean difference between the experimental and fitted tensile strength. The model allowed us to describe the load-strain curve of a geogrid from its tensile properties: & epsilon;(max), T-max and J(i). Regardless of the type of damage (in laboratory or in situ), the model was able to describe the load-strain curves of damaged samples using data from undamaged samples and scaling factors.
Equação constitutiva não-linear para representar o efeito da danificação mecânica no comportamento em tração de um geotêxtil não-tecido
Publication . Lombardi, Giovani; Pinho-Lopes, Margarida; Pereira, António B.; Paula, António Miguel
Neste artigo, aplicou-se um modelo constitutivo simples para descrever a resposta à tração não-linear de um geotêxtil não-tecido termoligado de polipropileno, bem como a influência de danificação mecânica na resposta do material. Os parâmetros do modelo constitutivo foram analisados e seu significado físico foi discutido. Avaliou-se a capacidade do modelo constitutivo em reproduzir a resposta em tração do geotêxtil intacto e após a danificação.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDP/00481/2020