Material Properties and Fatigue Safety Evaluation of Old Metal Bridges

2012 ◽  
Vol 525-526 ◽  
pp. 137-140
Author(s):  
Chun Sheng Wang ◽  
Hai Jun Sheng ◽  
Jing Yu Hu ◽  
Sheng Long Yan ◽  
Lan Duan
Keyword(s):  
Service Life ◽  
Yellow River ◽  
Safety Evaluation ◽  
Fatigue Property ◽  
Test Results ◽  
Lanzhou City ◽  
Remaining Service Life ◽  
Fatigue And Fracture ◽  
Cultural Relic ◽  
Truss Bridge

Lanzhou Zhongshan Bridge, which is located in the center of Lanzhou city, is a rivet truss bridge built in 1909. It is the first iron bridge over the Yellow River as well as a national cultural relic. An original steel angel cut off from Lanzhou Zhongshan Bridge was used to carry out a series of tests including material mechanics, fracture and fatigue property. Based on the test results, the fatigue and fracture safety was evaluated during the bridge remaining service life. Whats more, remaining service life of Lanzhou Zhongshan Bridge was calculated and found that the trucks weight more than 120 kN should be limited to ensure the safety.

Remaining Service Life of a 96 Year Old Riveted Truss Bridge

2004 ◽  
Vol 88 (2) ◽  
pp. 73-78
Author(s):  
Chunsheng Wang ◽  
Weizhen Chen ◽  
Airong Chen
Keyword(s):  
Service Life ◽  
Remaining Service Life ◽  
Truss Bridge

A Possible Basis for Nondestructive Characterization of Ropes of Nylon 6

1997 ◽  
Vol 503 ◽  
Author(s):  
H. Jiang ◽  
M. K. Davis ◽  
R. K. Eby ◽  
P. Arsenovic
Keyword(s):  
Tensile Strength ◽  
Service Life ◽  
Fiber Diameter ◽  
Structural Parameters ◽  
Crystal Form ◽  
Nylon 6 ◽  
Remaining Service Life ◽  
Nondestructive Characterization ◽  
Fractional Content

ABSTRACTPhysical properties and structural parameters have been measured for ropes of nylon 6 as a function of the number of use operations. The fractional content of the α crystal form, sound velocity, birefringence, tensile strength and length all increase systematically and significantly with increasing the number of use operations. The fractional content of the γ crystal form and fiber diameter decrease with use. These trends indicate that the measurement of such properties and structural parameters, especially the length, provide a possible basis for establishing a reliable, rapid, and convenient nondestructive characterization method to predict the remaining service life of nylon 6 ropes.

Preparation Techniques and Property Evaluations of Highly Air Permeable Needle-Punched Geotextiles

2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Service Life ◽  
Mechanical Strength ◽  
Pore Structure ◽  
Test Results ◽  
Needle Punching ◽  
Pet Fibers ◽  
Environmental Requirements ◽  
Preparation Techniques

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.

Remaining service life diagnostic technology of insulators for power distribution equipment

2009 ◽  
Vol 167 (2) ◽  
pp. 1-9
Author(s):  
Shinsuke Miki ◽  
Hiroshi Okazawa ◽  
Taketoshi Hasegawa ◽  
Sei Tsunoda ◽  
Hiroshi Inujima
Keyword(s):  
Service Life ◽  
Power Distribution ◽  
Remaining Service Life ◽  
Diagnostic Technology

scholarly journals Unbalanced Vibration Identification of Tangential Threshing Cylinder Induced by Rice Threshing Process

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Zhong Tang ◽  
Haotian Zhang ◽  
Yuepeng Zhou
Keyword(s):  
Service Life ◽  
Vibration Amplitude ◽  
Rotation Speed ◽  
Resonance Phenomenon ◽  
Test Results ◽  
Axial Vibration ◽  
Ansys Software ◽  
Cylinder Axis ◽  
Vibration State ◽  
Rice Stalks

Unbalanced vibration of tangential threshing cylinder increased the grain loss, shortened service life of the cylinder, and resulted in structural resonance during the rice threshing process. In this paper, the vibration amplitude and frequency of tangential threshing cylinder shaft were tested, and the vibration state of tangential threshing cylinder was identified. The restricted and working modalities of tangential threshing cylinder were solved by ANSYS software. Then, by comparing the resonance phenomenon between the inherent constraint frequency and the rotation speed frequency, the shaft vibration under the idle condition of tangential threshing cylinder was tested and analyzed. According to the axial vibration and axial trajectory of the cylinder, the inherent properties and characteristics of unbalanced vibration were revealed. Test results showed that when the tangential threshing cylinder was at idling and no-load state, the amplitude of vibration in the feed direction of straw flow was -0.049~0.060 mm, and the average vibration amplitude was 0.013 mm. As rice flowed along the tangential threshing cylinder, the vibration amplitude slightly increased. The trend and phase of each trajectory were similar, although the amplitude of each trajectory was different. The tangential threshing cylinder axis trajectory was flat oval. Unbalanced vibration was induced by the rice stalks in the concave gap.

scholarly journals Maintenance Modelling of Ceramic Claddings in Pitched Roofs Based on the Evaluation of Their In Situ Degradation Condition

2020 ◽  
Vol 5 (9) ◽  
pp. 77
Author(s):  
Cláudia Ferreira ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Ilídio S. Dias ◽  
Inês Flores-Colen
Keyword(s):  
Service Life ◽  
Maintenance Strategies ◽  
Total Replacement ◽  
Remaining Service Life ◽  
In Situ Degradation ◽  
Maintenance Policies ◽  
And Performance ◽  
The Impact ◽  
Maintenance Model

Existing maintenance policies have several limitations, mainly due to the lack of knowledge regarding the durability and performance of buildings. Usually, the maintenance policies are insufficiently accurate, neglecting the risk of failure over time and the global costs associated with repairs. In this study, a condition-based maintenance model, based on Petri nets, is proposed to evaluate the impact of three maintenance strategies of ceramic claddings in pitched roofs (CCPR): MS1—only total replacement; MS2—composed of total replacement and minor intervention and MS3—composed of total replacement, minor intervention and cleaning operations. In this study, 146 CCPR were inspected in situ, with a total area of 43,991.6 m2. The remaining service life of the CCPR; the global costs over the claddings’ lifetime (considering inspection, maintenance, replacement and disposal costs); the claddings’ degradation condition and the number of replacements during the time horizon are used to evaluate the performance of the different maintenance strategies through a simplified multi-criteria analysis. The results show that the gains in performance, in terms of expected service life and durability, of the consideration of preventive maintenance actions (minor interventions or cleaning operations) outweigh the increase of the operation costs.

Research on Optimal Index Set Based on Consequence-Reverse-Diffusion Method of Yellow River Downstream Embankment

2014 ◽  
Vol 955-959 ◽  
pp. 3020-3025
Author(s):  
Feng Feng ◽  
Hong Tao Jia ◽  
Xiao Ming Rong
Keyword(s):  
Index System ◽  
Influence Factor ◽  
Yellow River ◽  
Influence Factors ◽  
Safety Evaluation ◽  
Diffusion Method ◽  
The Yellow River ◽  
Index Set ◽  
Main Factors ◽  
River Embankment

Constructing a scientific, reasonable, all-encompassing, and representative-strong index system is an important premise and guarantee for the good embankment-safety-evaluation of Yellow River. Therefore, the embankment safety-influencing-factor identification has been raised based on consequence-reverse-diffusion method, which can be used to seek the main factors leading to accidents by reverse-thinking and reverse-diffusion way. The main factors which lead to the embankment accident shall be found out according to the accident form, then spreading to the specific influence-factor. As a result, the author has made a classification and extraction for the identified safety-influence-factors, and constructed the optional index-set and index-system for the Yellow River embankment-safety-evaluation after analyzing the content of the safety-influence-factors, which has laid a solid foundation for further embankment safety assessment for the Yellow River embankment construction.

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