China
Africa
Explore chapters and articles related to this topic
Effect of Oscillation Frequency on Microstructure and Tensile Properties of Linear Friction Welded Ti-6Al-4V Alloy Joints
Published in Samson Jerold Samuel Chelladurai, Suresh Mayilswamy, Arun Seeralan Balakrishnan, S. Gnanasekaran, Green Materials and Advanced Manufacturing Technology, 2020
C. Mukundhan, P. Sivaraj, C. Rajarajan, Vijay Petley, Shweta Verma, V. Balasubramanian
The tensile properties, such as yield strength, ultimate tensile strength and elongation of the defect-free joints (15 Hz and 17 Hz oscillatory frequencies) are shown in Table 19.4. The 15 Hz and 17 Hz oscillatory frequency joints exhibited 94% and 96% joint efficiencies, which resemble the characteristic feature of the LFW process. The tensile strength of the welded joint found close to the base material indicates the coalescence of the process. Figure 19.4 represents the strength-to-displacement graph for 15 Hz and 17 Hz oscillation frequency. The superior strength of the joint is also due to the nucleation of fine grains in the WCZ. The nucleation of these fine grains is due to the fine rubbing action at the interface of the process, which helps the material to plasticize (Wang et al. 2019; Hua et al. 2014). Moreover, both the joints failed in the TMAZ region because the coarser grains formed as a result of heat dissipation through the process. The fall in the percentage reduction of elongation also indicates the reduction in ductility of the LFW joints (Zhao and Fu 2020).
Finite element analysis of pressuremeter tests using critical state soil models
Published in G.N. Pande, S. Pietruszczak, H.F. Schweiger, Numerical Models in Geomechanics, 2020
M. Charles, H. S. Yu, D. Sheng
The results of the numerical tests using the four different critical state models are shown in Tables 1, 2, 3, and 4. Table 1 contains the results for tests using the modified Cam clay model with seven different values of overconsolidation ratio (OCR). It is interesting to know that for OCR of 2, the undrained loading of the modified Cam clay model behaves in the same way as that of the elastic-plastic von Mises plasticity model. The error induced in calculating the undrained shear strength when the graph is not perfectly linear in the plastic section could be up to 3% although an error of less than 1% in general is more likely. The undrained shear strength was calculated using both central strain and volumetric strain values. As the the results of the two methods were essentially the same only the central strain results are shown.
Feature Extraction Techniques
Published in Awais Ahmad Khan, Emad Abouel Nasr, Abdulrahman Al-Ahmari, Syed Hammad Mian, Integrated Process & Fixture Planning, 2018
Awais Ahmad Khan, Emad Abouel Nasr, Abdulrahman Al-Ahmari, Syed Hammad Mian
The graph-based algorithms arrange the B-rep of a part into a graph structure. These graphs can have faces, edges, or vertices as nodes, and any of the other two entities as arcs [15]. These graphs are split into subgraphs using a well-defined algorithm. The strength of the graph-based approaches lies in their ability to recognize the isolated features while they have shortcomings in recognizing the interacting features and multiple interpretations [29,31]. It requires extensive preprocessing to construct the graphs and additional computation to extract the feature subgraph from the rest of the graph [15]. It is an efficient technique to recognize simple as well as complex features [20]. The advantages of graph-based recognition can be summarized as follows [29]: Applies to several domains, that is, it is not limited only to the machiningAllows the users to add new feature types without changing the codeIs suitable for incremental feature modelingRecognizes isolated features effectively
Influence of metakaolin as a partial replacement of cement on characteristics of concrete exposed to high temperatures
Published in Journal of Sustainable Cement-Based Materials, 2021
Ramezan Ali Izadifard, Mehrdad Abdi Moghadam, Mohammad Mahdi Sepahi
To show the relationship between the tensile strength and compressive strength at high temperatures, the compressive strength-tensile strength graph for all specimens is shown in Figure 3. According to this diagram, with the increase in the compressive strength, the tensile strength improves. By applying regression analysis, the relationship between these two parameters is presented with a coefficient of variation of 0.74. The relatively low coefficient of variation can be related to the complicated behavior of concrete at high temperatures. For example, a sharp loss of tensile strength at 200 °C is one of these behaviors.
A dislocation-based stress-strain gradient plasticity model for strength and ductility in materials with gradient microstructures
Published in Philosophical Magazine, 2018
Mehdi Hamid, Hao Lyu, Hussein Zbib
Figure 4(a) provides a strength and ductility graph for all 20 nano/microstructures and their equivalent homogenised structures. They are compared with experimental results from the literature. Results in Figure 4(a) for the homogeneous microstructures follow the expected banana-shape curve, as Hall-Petch predicts. However, comparing the homogeneous microstructures results to the heterogeneous ones reveals that the gradient microstructures have higher strength and ductility, as shown in Figure 4(a). This suggests that the number of nanolayers in the structure can be an essential parameter that affects the strength and ductility of the samples.
Towards effective resolution approaches for solving the sum coloring problem
Published in Journal of Experimental & Theoretical Artificial Intelligence, 2020
Olfa Harrabi, Jouhaina Chaouachi
where is cardinality of the color class and . This minimal sum is called chromatic sum and usually denoted by . The number of colors used to obtain the chromatic sum is called the strength of the graph.