Publicação
Dissipation boundaries for bender element experiments on geomaterials based on experimental and computational models
| Resumo: | The bender element (BE) test is widely employed in geotechnical engineering for measuring the shear wave velocity (V<inf>s</inf>) and, consequently, the small-strain shear modulus (G<inf>0</inf>), due to its ease of application, integration into geotechnical devices, and effectiveness in real-world projects. However, signal distortion, primarily caused by shear and compression wave interference, remains a significant challenge, leading to unreliable measurements. This study, conducted as part of the CEN-DynaGeo and INTENT projects, introduces 3D-printed dissipation boundaries designed to mitigate compression wave interference and enhance signal clarity. Three dissipation boundary shapes including rings, spikes, and vertical strips were evaluated in a custom-designed vertical compression acrylic cell equipped with bender elements. The shapes were designed based on the numerical modeling of the BE experiment, conducted using the FreeHyTE software, which employs hybrid-Trefftz finite elements. Experimental results demonstrated that all dissipation boundaries effectively attenuated the compression wave peaks, with efficiencies depending on their shapes. Under vertical stress of 50 kPa and input frequency of 2 kHz in specimens with a void ratio of 0.85, compression wave peak reductions of 60 %, 46 %, and 19.9 % were observed for the ring, spike, and vertical strip boundaries, respectively. The proposed dissipation boundary technique offers a novel solution to improve the reliability of bender element testing in geotechnical applications. |
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| Autores principais: | Moldovan, Ionuţ Dragoş |
| Outros Autores: | Roshan, Mohammad Jawed; Azenha, Miguel; Correia, A. Gomes |
| Assunto: | Bender element Dissipation boundary Hybrid-Trefftz finite element |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | The bender element (BE) test is widely employed in geotechnical engineering for measuring the shear wave velocity (V<inf>s</inf>) and, consequently, the small-strain shear modulus (G<inf>0</inf>), due to its ease of application, integration into geotechnical devices, and effectiveness in real-world projects. However, signal distortion, primarily caused by shear and compression wave interference, remains a significant challenge, leading to unreliable measurements. This study, conducted as part of the CEN-DynaGeo and INTENT projects, introduces 3D-printed dissipation boundaries designed to mitigate compression wave interference and enhance signal clarity. Three dissipation boundary shapes including rings, spikes, and vertical strips were evaluated in a custom-designed vertical compression acrylic cell equipped with bender elements. The shapes were designed based on the numerical modeling of the BE experiment, conducted using the FreeHyTE software, which employs hybrid-Trefftz finite elements. Experimental results demonstrated that all dissipation boundaries effectively attenuated the compression wave peaks, with efficiencies depending on their shapes. Under vertical stress of 50 kPa and input frequency of 2 kHz in specimens with a void ratio of 0.85, compression wave peak reductions of 60 %, 46 %, and 19.9 % were observed for the ring, spike, and vertical strip boundaries, respectively. The proposed dissipation boundary technique offers a novel solution to improve the reliability of bender element testing in geotechnical applications. |
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