scholarly journals Experimental and Numerical Investigation of Old Masonry Wall Using a Macro-Modeling Approach

2020 ◽  
Vol 14 (1) ◽  
pp. 334-349
Author(s):  
Ambareesh Kumar ◽  
Kumar Pallav

Background: A 3-D finite element model of the internal masonry wall of a 103-year-Old Senate hall, Allahabad University, has been modeled using macro-modeling approaches. The masonry wall is an excellent example of Indo-Saracenic style architecture used by Britishers during the late 19th Century, which is a unification of the Mughal and Colonial architecture. Methods: Non-destructive Test (NDT) has been conducted to estimate is compressive strength and Young’s modulus of the wall. Compressive strength of the brick masonry and stone arch was estimated in the range of 10.5-12.5 MPa and 18.6-21.2 MPa, respectively, whereas Young’s Modulus was estimated in the range of 1800-5000 MPa and 5500-8000 MPa (outlier not considered). Finite Element model was prepared using the macro-modeling approach. Results: The gravity load analysis shows that the wall is stable, and its geometrical configuration is safe with maximum Von-Mises stress of 5.38 MPa and deformation of 2.27 mm. The results of the first six modes are presented. Further, in the absence of a recorded ground motion for the Prayag city, synthetic ground motion is simulated for 25th April 2015 Nepal earthquake (Mw) using a stochastic finite fault model. Conclusion: Evaluated behaviour of the internal masonry wall is shown in the form of acceleration, deformation and stress response.

2020 ◽  
Vol 10 (17) ◽  
pp. 5973
Author(s):  
Paul Didier ◽  
Boris Piotrowski ◽  
Gael Le Coz ◽  
David Joseph ◽  
Pierre Bravetti ◽  
...  

The present work proposes a parametric finite element model of the general case of a single loaded dental implant. The objective is to estimate and quantify the main effects of several parameters on stress distribution and load transfer between a loaded dental implant and its surrounding bone. The interactions between them are particularly investigated. Seven parameters (implant design and material) were considered as input variables to build the parametric finite element model: the implant diameter, length, taper and angle of inclination, Young’s modulus, the thickness of the cortical bone and Young’s modulus of the cancellous bone. All parameter combinations were tested with a full factorial design for a total of 512 models. Two biomechanical responses were identified to highlight the main effects of the full factorial design and first-order interaction between parameters: peri-implant bone stress and load transfer between bones and implants. The description of the two responses using the identified coefficients then makes it possible to optimize the implant configuration in a case study with type IV. The influence of the seven considered parameters was quantified, and objective information was given to support surgeon choices for implant design and placement. The implant diameter and Young’s modulus and the cortical thickness were the most influential parameters on the two responses. The importance of a low Young’s modulus alloy was highlighted to reduce the stress shielding between implants and the surrounding bone. This method allows obtaining optimized configurations for several case studies with a custom-made design implant.


2016 ◽  
Vol 258 ◽  
pp. 233-236 ◽  
Author(s):  
Shun Fa Hwang ◽  
Hsuan Ting Liu

The purpose of this work is to study a new composite material consisting of polyurethane (PU) resin and carbon fiber fabric. This PU resin is superior in impact, viscosity, low curing temperature, and short curing time. If this resin is combined with fiber fabric by vacuum assisted resin transfer method, the fabrication time will be short. Since it is a braided composite, it’s important to have a model to predict the elastic constants for different braid angels. To predict the elastic constants including Young’s modulus, shear modulus, and Poisson’s ratio, a finite element model is established. In this model a braided layer is treated as two uni-directional layers. Then, the elastic constants of this composite with different braid angels are estimated. After that, the composites with different braid angels are fabricated and tested to obtain the elastic constants, and the comparison with the finite element results is made. The results indicate that the agreement is very good for the Young’s modulus. For the Poisson’s ratio, the difference between the prediction and the measurement is reasonable. From the comparison, it can be concluded that the finite element model is good. Then, this model is used to predict all in-plane elastic constants for arbitrary braid angles.


Sign in / Sign up

Export Citation Format

Share Document