Research on Crack Property of Concrete Based on Fracture Mechanics

2010 ◽  
Vol 160-162 ◽  
pp. 1699-1703
Author(s):  
Wei He ◽  
Rong He ◽  
Heng Xiang Zheng
Keyword(s):  
Numerical Simulation ◽  
Stress State ◽  
Fracture Mechanics ◽  
Field Test ◽  
Bridge Deck ◽  
Equivalent Stress ◽  
Simulation Method ◽  
Critical Value ◽  
Fracture Angle ◽  
Bridge Deck Pavement

The type of I-II compound crack in bridge deck pavement is most popular. Based on the theory of fracture mechanics the least equivalent stress method is put forward and used to study the problem of concrete cracks. The method could be used to determine the fracture angle of I-II compound crack. For the cracked deck pavement, the stress state could be determined by field test or numerical simulation method and then calculate the equivalent stress near the point by Matlab. The examples show that when the equivalent stress gets to the critical value the crack will develop along fracture angle which could be calculated from the least equivalent stress method. The theory value of fracture angle is basically accurate with the test one.

scholarly journals Contrasting the Role of Pores on the Stress State Dependent Fracture Behavior of Additively Manufactured Low and High Ductility Metals

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3657
Author(s):  
Alexander E. Wilson-Heid ◽  
Erik T. Furton ◽  
Allison M. Beese
Keyword(s):  
Stainless Steel ◽  
Stress State ◽  
Pore Size ◽  
Fracture Behavior ◽  
316L Stainless Steel ◽  
Equivalent Stress ◽  
Failure Behavior ◽  
High Ductility ◽  
State Dependent ◽  
Fracture Models

This study investigates the disparate impact of internal pores on the fracture behavior of two metal alloys fabricated via laser powder bed fusion (L-PBF) additive manufacturing (AM)—316L stainless steel and Ti-6Al-4V. Data from mechanical tests over a range of stress states for dense samples and those with intentionally introduced penny-shaped pores of various diameters were used to contrast the combined impact of pore size and stress state on the fracture behavior of these two materials. The fracture data were used to calibrate and compare multiple fracture models (Mohr-Coulomb, Hosford-Coulomb, and maximum stress criteria), with results compared in equivalent stress (versus stress triaxiality and Lode angle) space, as well as in their conversions to equivalent strain space. For L-PBF 316L, the strain-based fracture models captured the stress state dependent failure behavior up to the largest pore size studied (2400 µm diameter, 16% cross-sectional area of gauge region), while for L-PBF Ti-6Al-4V, the stress-based fracture models better captured the change in failure behavior with pore size up to the largest pore size studied. This difference can be attributed to the relatively high ductility of 316L stainless steel, for which all samples underwent significant plastic deformation prior to failure, contrasted with the relatively low ductility of Ti-6Al-4V, for which, with increasing pore size, the displacement to failure was dominated by elastic deformation.

Developing cold-mixed epoxy resin-based ultra-thin antiskid surface layer for steel bridge deck pavement

2021 ◽  
Vol 291 ◽  
pp. 123366
Author(s):  
Yang Liu ◽  
Zhendong Qian ◽  
Xijun Shi ◽  
Yuheng Zhang ◽  
Haisheng Ren
Keyword(s):  
Surface Layer ◽  
Epoxy Resin ◽  
Bridge Deck ◽  
Steel Bridge ◽  
Bridge Deck Pavement

scholarly journals A Comprehensive Life-Cycle Cost Analysis Approach Developed for Steel Bridge Deck Pavement Schemes

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 565
Author(s):  
Changbo Liu ◽  
Zhendong Qian ◽  
Yang Liao ◽  
Haisheng Ren
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Bridge Deck ◽  
Analysis Approach ◽  
Steel Bridge ◽  
User Cost ◽  
Construction Quality ◽  
Concrete System ◽  
Traffic Conditions ◽  
Bridge Deck Pavement

This study aims to evaluate the economy of a steel bridge deck pavement scheme (SBDPS) using a comprehensive life-cycle cost (LCC) analysis approach. The SBDPS are divided into the “epoxy asphalt concrete system”(EA system) and“ Gussasphalt concrete system”(GA system) according to the difference in the material in the lower layer of the SBDPS. A targeted LCC checklist, including manager cost and user cost was proposed, and a Markov-based approach was applied to establish a life-cycle performance model with clear probability characteristics for SBDPS. Representative traffic conditions were designed using a uniform design method, and the LCC of SBDPS under representative traffic conditions and different credibility (construction quality as a random factor) was compared. The reliability of the LCC analysis approach was verified based on the uncertainty analysis method. Based on an expert-scoring approach, a user cost weight was obtained to ensure it is considered reasonably in the LCC analysis. Compared with the cumulative traffic volume, the cumulative equivalent single axle loads (CESAL) have a closer relationship with the LCC. The GA system has better LCC when the CESAL is less, while the EA system is just the opposite. The breaking point of CESAL for the LCC of the EA system and the GA system is 15 million times. The LCC analysis of SBDPS should consider the influence of random factors such as construction quality. The comprehensive LCC analysis approach in this paper can provide suggestions for bridge-management departments to make a reasonable selection on SBDPS.

scholarly journals An Approach to Determine Optimal Bow Configuration of Polar Ships under Combined Ice and Calm-Water Conditions

2021 ◽  
Vol 9 (6) ◽  
pp. 680
Author(s):  
Hui Li ◽  
Yan Feng ◽  
Muk Chen Ong ◽  
Xin Zhao ◽  
Li Zhou
Keyword(s):  
Numerical Simulation ◽  
Water Resistance ◽  
Numerical Technique ◽  
Experimental Studies ◽  
Resistance Index ◽  
Simulation Method ◽  
Present Approach ◽  
Calm Water ◽  
Level Ice ◽  
Ice Resistance

Selecting an optimal bow configuration is critical to the preliminary design of polar ships. This paper proposes an approach to determine the optimal bow of polar ships based on present numerical simulation and available published experimental studies. Unlike conventional methods, the present approach integrates both ice resistance and calm-water resistance with the navigating time. A numerical simulation method of an icebreaking vessel going straight ahead in level ice is developed using SPH (smoothed particle hydrodynamics) numerical technique of LS-DYNA. The present numerical results for the ice resistance in level ice are in satisfactory agreement with the available published experimental data. The bow configurations with superior icebreaking capability are obtained by analyzing the sensitivities due to the buttock angle γ, the frame angle β and the waterline angle α. The calm-water resistance is calculated using FVM (finite volume method). Finally, an overall resistance index devised from the ship resistance in ice/water weighted by their corresponding weighted navigation time is proposed. The present approach can be used for evaluating the integrated resistance performance of the polar ships operating in both a water route and ice route.

A numerical simulation method for molten material behavior in nuclear reactors

2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida
Keyword(s):  
Numerical Simulation ◽  
Nuclear Reactors ◽  
Simulation Method ◽  
Material Behavior ◽  
Molten Material ◽  
Numerical Simulation Method
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