scholarly journals Transition of Failure Mode When Impact Load was Repeatedly Applied to SS400 Smooth Specimen

2018 ◽  
Vol 67 (11) ◽  
pp. 993-999 ◽  
Author(s):  
Hiroaki HASHIMOTO ◽  
Kenichiro HASHIMOTO ◽  
Koji MIMURA ◽  
Isamu RIKU ◽  
Tsutomu UMEDA
Keyword(s):  
Failure Mode ◽  
Impact Load ◽  
Smooth Specimen

A Comparative Study on the Impact Damage of Membrane Type LNGC Insulation System

2009 ◽  
Author(s):  
Min Sung Chun ◽  
Yong Suk Seo ◽  
Ito Hisasi ◽  
Wha Soo Kim ◽  
Byeong Jae Noh ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Failure Mode ◽  
Impact Load ◽  
Impact Damage ◽  
Structural Response ◽  
Structural Safety ◽  
Structural Behavior ◽  
Insulation System ◽  
Membrane Type ◽  
The Impact

To verify the structural safety under impact load caused by sloshing of LNG is one of the main issues in the design of membrane type LNG cargo containment system of LNG carrier. In order to estimate structural response under sloshing impact load, many kinds of studies including experimental test and numerical simulation have been done by various research groups such as shipyards, oil companies, universities as well as classification societies. In spite of these efforts, many uncertainties still exist to predict the structural behavior of LNG insulation system under sloshing impact load. Therefore, it can be regarded as a challenge to investigate dynamic response of LNG cargo insulation system against sloshing load. In this paper, Cooperative research results obtained by SHI-HHI-PNU-Lloyd-ABS-DNV JDP focused on the impact damage or failure mode of membrane type LNG cargo insulation system are summarized. A systematic experimental research is carried out to find out failure mode of the insulation system under impact load and criteria which can be applied for the design of LNG carrier. A series of dry drop tests as well as static compressive tests are carried out. The structural behavior of the specimen under impact load is recorded using ultrahigh-speed camera and reaction force is measured using load cells which are installed under bottom of the test facility. By analyzing recorded video, deformation history of the specimen at impact moment is obtained. The numerical simulations are also carried out for the dry drop test for verification purpose, It is expected that the insights observed from the systematic experiments and numerical simulations for the structural response of the LNG cargo insulation system subjected to the impact load can be effectively used as design guide for evaluation of the integrity of structural components of LNG cargo hold system.

Study on Mechanism of Tap Breakage in Low Frequency Torsional Vibration Tapping

2010 ◽  
Vol 37-38 ◽  
pp. 1306-1310
Author(s):  
Feng Qi Han ◽  
Zhi Zun Li ◽  
De Yuan Zhang
Keyword(s):  
Stress State ◽  
Service Life ◽  
Tensile Stress ◽  
Failure Mode ◽  
Torsional Vibration ◽  
Impact Load ◽  
Low Frequency ◽  
Rake Angle ◽  
Shock Resistance ◽  
Large Tensile Stress

Early breakage of tap often occurs when tapping on difficult-to-cut materials with the method of low frequency torsional vibration tapping, which decreases the technological effect and restricts its application. The effect of impact load on tap breakage in vibration tapping was analyzed, and the stress state in tap teeth was simulated by FEM, on this basis, it is concluded that too large tensile stress in tap teeth is the main cause of early breakage of tap. To reduce the tensile stress and enhance the shock resistance of tap teeth, the tap should be ground to minor negative rake angle. Experiments showed that the failure mode of grinded taps changed to wear, and thereby the service life of tap was prolonged significantly.

scholarly journals Experimental and Numerical Analysis of Hollow and Solid Reinforced Concrete Piers under Static and Impact Loadings

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Pengfei Yao ◽  
Junyu Zhu ◽  
Lu Zhu ◽  
Hai Fang ◽  
Changgen Qian
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Failure Modes ◽  
Impact Force ◽  
Impact Load ◽  
Experimental Results ◽  
Impact Behavior ◽  
Low Velocity ◽  
Process Failure ◽  
Damage Process

Collision on reinforced concrete (RC) piers by moving vessels or vehicles is a significant issue. This paper presents the static and impact behavior of RC piers with different hollow ratios. Three specimens were statically tested to obtain the load-displacement response. Low-velocity collision on eleven RC piers was conducted under the same velocity of 2.42 m/s. The damage process, failure mode, and force response were comprehensively analyzed. The experimental results indicate that the hollow ratio plays a significant role in the failure mode and ultimate load of RC piers under static and impact loadings. For RC piers with a hollow ratio of 0 and 0.4, the global failure dominated the damage process. However, failure of piers with a hollow ratio of 0.6 was governed by the local damage near the loading point. The static load capacities of the RC piers with a hollow ratio of 0.4 and 0.6 were 1.27% and 60.5% smaller than that of the solid pier, respectively. RC piers with a higher hollow ratio or lighter drop weight suffer smaller peak impact force. The increase of the longitudinal reinforcements leads to a promotion of the peak and mean impact force. Furthermore, the numerically predicted failure modes and impact load response show satisfactory agreement with the experimental results.

Impact Response and Failure Mode for Single-Layer Geodesic Spherical Domes under Impact Load

2013 ◽  
Vol 351-352 ◽  
pp. 80-84
Author(s):  
Duo Zhi Wang ◽  
Feng Fan ◽  
Xu Dong Zhi ◽  
Jun Wu Dai
Keyword(s):  
Dynamic Response ◽  
Failure Mode ◽  
Failure Modes ◽  
Impact Load ◽  
Single Layer ◽  
Impact Response ◽  
Impact Location ◽  
Parametric Analyses ◽  
The Impact ◽  
Local Dent

Based on the ANSYS/LS-DYNA software, the analysis for the 40m span geodesic spherical domes under impact load is carried out. By changing the mass of impact object, impact velocity and impact location, the parametric analyses on the dynamic response of the structures under the impact loading are carried out. The three failure modes of the spherical domes are summed up: local dent of structure and global collapse of structure, Punch failure of structure. Then the characteristics of the dynamic response of the structure with different failure mode, such as the impact course, impact load, speed of nodes, displacement of nodes, and stress of bars, are investigated. It is further improvement of failure mode for single-layer reticulated dome under impact.

Analytical electron microscopy of grain boundaries in Al-Cu metallizations

1992 ◽  
Vol 50 (2) ◽  
pp. 1684-1685
Author(s):  
J. R. Michael ◽  
A. D. Romig ◽  
D. R. Frear
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuits ◽  
Failure Mode ◽  
Current Density ◽  
Thermal History ◽  
Analytical Electron Microscopy ◽  
Cu Metallization ◽  
Analytical Electron ◽  
Interconnect Lines

Al with additions of Cu is commonly used as the conductor metallizations for integrated circuits, the Cu being added since it improves resistance to electromigration failure. As linewidths decrease to submicrometer dimensions, the current density carried by the interconnect increases dramatically and the probability of electromigration failure increases. To increase the robustness of the interconnect lines to this failure mode, an understanding of the mechanism by which Cu improves resistance to electromigration is needed. A number of theories have been proposed to account for role of Cu on electromigration behavior and many of the theories are dependent of the elemental Cu distribution in the interconnect line. However, there is an incomplete understanding of the distribution of Cu within the Al interconnect as a function of thermal history. In order to understand the role of Cu in reducing electromigration failures better, it is important to characterize the Cu distribution within the microstructure of the Al-Cu metallization.

Behavior of RC Beams Strengthened by CFRP and Steel Rope under Frequent Impact Load

2018 ◽  
Vol 1 (1) ◽  
pp. 30-42
Author(s):  
Muataz Ali ◽  
◽  
Yaseen Saleh ◽  
Luna Al Hasani ◽  
Ammar Khazaal ◽  
...  
Keyword(s):  
Impact Load ◽  
Rc Beams ◽  
Steel Rope

Risk analysis of cutting system under intuitionistic fuzzy environment

2020 ◽  
Vol 1 (1) ◽  
pp. 162-173
Author(s):  
Dinesh Kumar Kushwaha ◽  
◽  
Dilbagh Panchal ◽  
Anish Sachdeva ◽  
◽  
...  
Keyword(s):  
Risk Assessment ◽  
Failure Mode ◽  
Thermal Power ◽  
Failure Detection ◽  
Engineering System ◽  
Effect Analysis ◽  
Intuitionistic Fuzzy ◽  
Mode Effect ◽  
Cutting System ◽  
Failure Mode Effect Analysis

Failure Mode Effect Analysis (FMEA) is popular and versatile approach applicable to risk assessment and safety improvement of a repairable engineering system. This method encompasses various fields such as manufacturing, healthcare, paper mill, thermal power industry, software industry, services, security etc. in terms of its application. In general, FMEA is based on Risk Priority Number (RPN) score which is found by product of probability of Occurrence (O), Severity of failure (S) and Failure Detection (D). As human judgement is approximate in nature, the accuracy of data obtained from FMEA members depend on degree of subjectivity. The subjective knowledge of members not only contains uncertainty but hesitation too which in turn, affect the results. Fuzzy FMEA considers uncertainty and vagueness of the data/ information obtained from experts. In order to take into account, the hesitation of experts and vague concept, in the present work we propose integrated framework based on Intuitionistic Fuzzy- Failure Mode Effect Analysis (IF-FMEA) and IF-Technique for Order Preference by Similarity to Ideal Solution (IF-TOPSIS) techniques to rank the listed failure causes. Failure cause Fibrizer (FR) was found to be the most critical failure cause with RPN score 0.500. IF-TOPSIS has been implemented within IF-FMEA to compare and verify ranking results obtained by both the IF based approaches. The proposed method was presented with its application for examining the risk assessment of cutting system in sugar mill industry situated in western Uttar Pradesh province of India. The result would be useful for the plant maintenance manager to fix the best maintenance schedule for improving availability of cutting system.

Sign in / Sign up

Export Citation Format

Share Document