The characteristics of cargo temperature rising in reefer container under refrigeration-failure condition

2021 ◽  
Vol 123 ◽  
pp. 1-8
Author(s):  
Ankang Kan ◽  
Tongzhou Wang ◽  
Wenbing Zhu ◽  
Dan Cao
Keyword(s):  
Failure Condition

Analysis and Modeling of Defects in Unsupported Overhanging Features in Micro-Stereolithography

2016 ◽  
Author(s):  
Vito Basile ◽  
Francesco Modica ◽  
Irene Fassi
Keyword(s):  
Finite Element ◽  
Numerical Models ◽  
Numerical Approach ◽  
Fe Analysis ◽  
Test Cases ◽  
Layer By Layer ◽  
Failure Condition ◽  
Micro Scale ◽  
Part Geometry ◽  
Shape Component

In the present paper, a numerical approach to model the layer-by-layer construction of cured material during the Additive Manufacturing (AM) process is proposed. The method is developed by a recursive mechanical finite element (FE) analysis and takes into account forces and pressures acting on the cured material during the process, in order to simulate the behavior and investigate the failure condition sources, which lead to defects in the final part geometry. The study is focused on the evaluation of the process capability Stereolithography (SLA), to build parts with challenging features in meso-micro scale without supports. Two test cases, a cantilever part and a bridge shape component, have been considered in order to evaluate the potentiality of the approach. Numerical models have been tuned by experimental test. The simulations are validated considering two test cases and briefly compared to the printed samples. Results show the potential of the approach adopted but also the difficulties on simulation settings.

scholarly journals The Out-of-Plane Compression Behavior of Cross-Ply AS4/PEEK Thermoplastic Composite Laminates at High Strain Rates

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2312 ◽  
Author(s):  
Huiran Zou ◽  
Weilong Yin ◽  
Chaocan Cai ◽  
Bing Wang ◽  
Ankang Liu ◽  
...  
Keyword(s):  
Composite Laminates ◽  
High Strain ◽  
Damage Mechanism ◽  
Strain Rates ◽  
Failure Condition ◽  
High Strain Rates ◽  
Peek Composite ◽  
Out Of Plane ◽  
Complete Failure ◽  
Plane Compression

The dynamic mechanical behavior of thermoplastic composites over a wide range of strain rates has become an important research topic for extreme environmental survivability in the fields of military protection, aircraft safety, and aerospace engineering. However, the dynamic compression response in the out-of-plane direction, which is one of the most important loading conditions resulting in the damage of composite materials, has not been investigated thoroughly when compared to in-plane compression and tensile behavior under high strain rates. Thus, we used split Hopkinson pressure bar (SHPB) tests to conduct the out-of-plane compression test of cross-ply carbon fiber-reinforced polyetheretherketone (AS4/PEEK) composite laminates. Afterward, the damage mechanism under different strain rates was characterized by the macrostructure morphologies and scanning electron microscope micrographs. Two major cases of the incomplete failure condition and complete failure condition were discussed. Dynamic stress-strain curves expound the strain rates dependencies of elastic modulus, failure strength, and failure strain. An obvious spring-back process could be observed under incomplete failure tests. For the complete failure tests, secondary loading could be observed by reconstructing and comparing the dynamic response history. Lastly, various failure modes that occurred in different loading strain rates illustrate that the damage mechanism also shows obvious strain rate sensitivity.

Induction Motor Fault Diagnosis Based on Multi-Sensor Fusion Under High Noise and Sensor Failure Condition

2021 ◽  
Author(s):  
Zhiyu Tao ◽  
Pengcheng Xia ◽  
Yixiang Huang ◽  
Dengyu Xiao ◽  
Yuxiang Wuang ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Induction Motor ◽  
Sensor Fusion ◽  
Sensor Failure ◽  
Failure Condition ◽  
High Noise

Research on the Performance of Check Valve at a Long Distance Pumping System

2019 ◽  
Author(s):  
Huili Bi ◽  
Honggang Fan ◽  
Bin Cao ◽  
Yu Xu
Keyword(s):  
Pump Power ◽  
Flow Velocity ◽  
Negative Pressure ◽  
Characteristic Time ◽  
Check Valve ◽  
Failure Condition ◽  
Long Distance ◽  
Pressure Transient ◽  
Power Failure ◽  
Pumping System

Abstract Experimental investigations of dynamic characteristics of the check valve are a contribution work to provide boundary condition to check valve mathematical simulation. The closure process of the check valve was tested. The changing processes of inlet and outlet pressure were performed. Based on the experiment system and the measured quantities, mathematical models were established to study the test. Numerical calculation was mainly focus on when valve starting to close and the closing characteristic time. The paper simulated the different minimum velocities that the valve started to close at. Simulation results approximated to test data when the check valve started to close at a larger flow velocity and a shorter closing characteristic time. The closing characteristic time was discussed when check valves closing on a certain velocity. Following the closure rule of check valve got during the simulation, the paper studied the check valve acting on a long distance pumping system. Two part contents were studied: only check valve arranged along pipeline, both air admission valve and check valves arranged. Along the pipeline seven check valves were arranged, the pump power failure condition was calculated and check valves were closed because of the flow velocity decreased. The result showed negative pressure was large when installed just a finite number of check valves along pipeline. Gas admission valves were arranged to negative pressure prevention. Two check valves were respectively arranged at the pump outlet and pipeline. The pressure transient peak at pump outlet will be dropped a lot with the check valve at pipeline closed; the maximum pressure transient peak along pipeline is appeared at check valve outlet on the pipeline under the pump power failure condition. The negative pressure in front pipes could be prevented by installing gas admission valve. Through the check valves and gas admission valves combined action, both the pressure and backflow were well controlled.

scholarly journals Unconscious decisions causing a failure condition of the 19th century brick ceiling

2018 ◽  
Vol 174 ◽  
pp. 03014
Author(s):  
Dariusz Bajno ◽  
Agnieszka Grzybowska ◽  
Rafał Tews
Keyword(s):  
19Th Century ◽  
Heavy Traffic ◽  
Ground Level ◽  
Traffic Load ◽  
School Building ◽  
Failure Condition ◽  
Sand Base ◽  
The 19Th Century

The article describes a hazard caused by deformation of a brick vault located under the dungeons of the gate tower of Zamek Górny in Opole at the turn of the 13th and the 14th centuries, which was used as a school building until 2017. The hazard identified in 2013 was found on the ground level of the building in a communication route of the heavy traffic load. Visual inspections and tests have demonstrated that the existing situation was caused by civil works performed at the dungeon level nearly 6 years earlier due to an unconsidered decision on removing debris and a backfill which filled entirely the lower tower storeys. The above actions resulted in removal of the base of the floor ‘laid on the ground’ in the 19th century [2][4]. In this article, an analysis was carried out to verify possibilities of unbelievable strength of the artificially formed flat vault, which was previously the floor supported on a debris and sand base.

An Exit Burr Model for Drilling of Metals

2000 ◽  
Vol 123 (4) ◽  
pp. 562-566 ◽  
Author(s):  
L. Ken Lauderbaugh Saunders ◽  
Craig A. Mauch
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Temperature Effects ◽  
Material Removal ◽  
Burr Formation ◽  
Failure Condition ◽  
Formation Model ◽  
Varying Thickness ◽  
Exit Burr ◽  
Thrust Forces

The mechanics of the formation of exit burrs for drilling metals are analyzed. A burr formation model is developed where the material in front of the drill is modeled as an axi-symmetric, circular plate of varying thickness. The drilling thrust forces are distributed as a pressure along the top surface of this plate. The stress state is then calculated. Material removal continues until a failure condition is reached. At the point of failure of the plate the remaining material is bent out to form the burr. The model also includes temperature effects. Experimental verification was conducted on 2024-T351 aluminum and on 7075-T561 aluminum. Two types of drill geometry were considered. The experiments were conducted with feeds from 0.05 to 0.35 mm/rev. The model accurately predicts the experimental data.

Pilot Expertise and Instrument Failure: Detecting Failure is Only Half the Battle

2007 ◽  
Vol 51 (19) ◽  
pp. 1306-1310
Author(s):  
Randy J. Brou ◽  
Stephanie M. Doane ◽  
Daniel W. Carruth ◽  
Gary L. Bradshaw
Keyword(s):  
Flight Simulator ◽  
Instrument Panel ◽  
Flight Performance ◽  
Failure Condition ◽  
Flight Experience ◽  
Novices And Experts

The present research examined novice and expert flight performance in simulated routine and announced instrument failure flight conditions. Pilots flew routine flight segments under simulated instrument flight rules, and were informed there would be an instrument failure at some point. Microsoft Flight Simulator was used to simulate a slow vacuum failure that impacted the attitude indicator and the failure was explicitly displayed in large letters on the instrument panel throughout the failure segment. Although novices and experts showed minimal axis deviations from optimal during routine flight maneuvers, the novice deviations increased significantly in the announced failure condition. The results have implications for the efficacy of instrument failure indicators for novice pilots with approximately ninety-five hours of flight experience.

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