scholarly journals Susceptibility of Impact Damage to Whole Apples Packaged Inside Molded Fiber and Expanded Polystyrene Trays

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1980
Author(s):  
Kyle Dunno ◽  
Isabel Stoeckley ◽  
Matthew Hofmeister
Keyword(s):  
Impact Damage ◽  
Free Fall ◽  
Middle Layer ◽  
Expanded Polystyrene ◽  
Mechanical Shock ◽  
Apple Industry ◽  
Impact Acceleration ◽  
Shock Protection ◽  
Bruise Susceptibility ◽  
The Impact

Postharvest damage, leading to loss and waste, continues to be a significant problem in the fresh produce industry. Trays, designed to reduce fruit-to-fruit contact, are utilized by the apple industry to minimize bruising of whole apples. During distribution, packaged apples are subjected to various supply chain hazards, which may lead to bruising damage. Currently, molded fiber (MF) and expanded polystyrene (EPS) trays transport whole apples from the packhouse to the retail outlet. Mechanical shock, by free-fall drop method, was used to evaluate the performance differences between the two trays and quantify the bruising characteristics of the apples. Results showed that the EPS trays provided better shock protection to the apple as compared to the MF tray, reducing the impact acceleration by more than 70%. Additionally, the bruise susceptibility was 40% less for the apples packaged inside the EPS trays, regardless of drop height. However, apples packaged in the middle layer trays were most susceptible to bruising damage, regardless of tray type.

Evaluation of residual strength in the basalt fiber reinforced composites under impact damage

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540004
Author(s):  
Yun-Hae Kim ◽  
Jin-Woo Lee ◽  
Kyung-Man Moon ◽  
Sung-Won Yoon ◽  
Tae-Sil Baek ◽  
...  
Keyword(s):  
Impact Damage ◽  
Basalt Fiber ◽  
Free Fall ◽  
Structure Design ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Environment Friendly ◽  
Reinforced Composite ◽  
The Impact

Composites are vulnerable to the impact damage by the collision as to the thickness direction, because composites are being manufactured by laminating the fiber. The understanding about the retained strength after the impact damage of the material is essential in order to secure the reliability of the structure design using the composites. In this paper, we have tried to evaluate the motion of the material according to the kinetic energy and potential energy and the retained strength after impact damage by testing the free fall test of the basalt fiber reinforced composite in the limelight as the environment friendly characteristic.

Use of thermomechanical pulp fibers from waste woods for making eco-friendly cushioning material

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 15-21 ◽  
Author(s):  
JI-YOUNG LEE ◽  
CHUL-HWAN KIM ◽  
JEONG-MIN SEO ◽  
HO-KYUNG CHUNG ◽  
KYUNG-KIL BACK ◽  
...  
Keyword(s):  
Impact Test ◽  
Product Distribution ◽  
Expanded Polystyrene ◽  
Thermomechanical Pulp ◽  
Fiber Structure ◽  
Pulp Fibers ◽  
Cationic Starch ◽  
Thermal Insulating ◽  
Surface Sizing ◽  
The Impact

Eco-friendly cushioning materials were made with thermomechanical pulps (TMPs) from waste woods collected from local mountains in Korea, using a suction-forming method without physical pressing. The TMP cushions had superior shock-absorbing performance, with lower elastic moduli than expanded polystyrene (EPS) or molded pulp. Even though the TMP cushions made using various suction times had many voids in their inner fiber structure, their apparent densities were a little higher than that of EPS and much lower than that of molded pulp. The addition of cationic starch contributed to an increase in the elastic modulus of the TMP cushions without increasing the apparent density, an effect which was different from that of surface sizing with starch. In the impact test, the TMP cushions showed a more ductile pattern than the brittle EPS. The porosity of the TMP cushion was a little less than that of EPS and much greater than that of molded pulp. The porous structure of the TMP cushions contributed to their excellent thermal insulating capacity, which was equivalent to that of EPS. In summary, the TMP packing cushions showed great potential for surviving external impacts during product distribution.

scholarly journals Numerical Investigation on the Ultimate Strength of Box Beams with Impact Damage

2020 ◽  
Author(s):  
Wei Xu ◽  
C. Guedes Soares
Keyword(s):  
Residual Stress ◽  
Ultimate Strength ◽  
Impact Damage ◽  
Ship Hulls ◽  
Four Point Bending ◽  
Impact Location ◽  
Box Beam ◽  
Box Beams ◽  
Fracture Damage ◽  
The Impact

AbstractThe objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage, as a model of what may occur in ship hulls. The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding, collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation. Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA. The ultimate moment and collapse modes are discussed considering the effect of impact location. The impact-induced deformation is introduced in the four-point bending simulation, and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact. It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant. The collapse modes also change when the impactor strikes on different locations. Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes. The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.

scholarly journals The Impact of Narrative Feedback, E-Learning Modules and Realistic Video and the Reduction of Misconception

2021 ◽  
Vol 11 (4) ◽  
pp. 158
Author(s):  
Abdul Halim ◽  
Elmi Mahzum ◽  
Muhammad Yacob ◽  
Irwandi Irwandi ◽  
Lilia Halim
Keyword(s):  
Biology Education ◽  
Free Fall ◽  
Percentage Reduction ◽  
Significant Treatment ◽  
Learning Modules ◽  
Physics Courses ◽  
Learning Platform ◽  
Quasi Experimental ◽  
E Learning ◽  
The Impact

Physics learning in universities utilized the Moodle-based e-learning media as an online learning platform. However, the effectiveness of remediating misconception using online media has not been widely researched. Therefore, this study was set to determine the level of misconception percentage reduction through the use of narrative feedback, the e-learning modules, and realistic video. The study was a quantitative approach with a quasi-experimental method involving 281 students who were taking basic physics courses in the Department of Physics, Chemistry, and Biology Education. The data collection used a three-tier diagnostic test based on e-learning at the beginning of the activity and after the treatment (posttest). The results of the data analysis with descriptive statistics show that the most significant treatment in reducing misconception percentage on the topic of free-fall motion was in the following order: narrative feedback, e-learning modules and realistic video. The misconception percentage reduction in the sub-concept of accelerated free- fall was effective for all types of the treatments.

Failure Mechanism Analysis of Electromagnetic Relay under Mechanical Impact

2013 ◽  
Vol 473 ◽  
pp. 39-45 ◽  
Author(s):  
Guo Wei Zhao ◽  
Yong Chen ◽  
De Yong Li ◽  
Bin Tang
Keyword(s):  
Failure Mechanism ◽  
Magnetic Circuit ◽  
Impact Damage ◽  
Engineering Application ◽  
Air Gap ◽  
Mechanism Analysis ◽  
Mechanical Impact ◽  
Electromagnetic Relay ◽  
Electromagnetic Relays ◽  
The Impact

The aim was to analyze failure mechanism of electromagnetic relay caused by mechanical impact. The principle of electromagnetic relays was studied and the effect of mechanical impact on electromagnetic relays was analyzed in this paper. Based on the established magnetic circuit model, the relationship of the magnetic field strength, the electromagnetic attraction and the impact damage degree was studied. Then, the damage intensity of mechanical impact on magnetic circuit was decided. Afterwards, the structure of electromagnetic relays was improved, and the mechanical impact simulation was studied by ANSYS. The results show that the uncontrollability of electromagnetic relay is mainly caused by air gap, which is aroused by mechanical impact; in addition, the size of air gap is inversely proportional to electromagnetic attraction force. Moreover, the improved structure of relays can increase impact resistance and broaden the scope of engineering application of electromagnetic relay.

IMPACT RESISTANCE PROPERTIES OF KEVLAR/GLASS FIBER HYBRID COMPOSITE LAMINATES

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Norazean Shaari ◽  
Aidah Jumahat ◽  
M. Khafiz M. Razif
Keyword(s):  
Glass Fiber ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Impact Damage ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Slight Reduction ◽  
Depth Of Penetration ◽  
Damage Degree ◽  
The Impact

In this paper, the impact behavior of Kevlar/glass fiber hybrid composite laminates was investigated by performing the drop weight impact test (ASTM D7136). Composite laminates were fabricated using vacuum bagging process with an epoxy matrix reinforced with twill Kevlar woven fiber and plain glass woven fiber. Four different types of composite laminates with different ratios of Kevlar to glass fiber (0:100, 20:80, 50:50 and 100:0) were manufactured. The effect of Kevlar/glass fiber content on the impact damage behavior was studied at 43J nominal impact energy. Results indicated that hybridization of Kevlar fiber to glass fiber improved the load carrying capability, energy absorbed and damage degree of composite laminates with a slight reduction in deflection. These results were further supported through the damage pattern analysis, depth of penetration and X-ray evaluation tests. Based on literature work, studies that have been done to investigate the impact behaviour of woven Kevlar/glass fiber hybrid composite laminates are very limited. Therefore, this research concentrates on the effect of Kevlar on the impact resistance properties of woven glass fibre reinforced polymer composites.

Collisions between liquid drops

1978 ◽  
Vol 287 (1349) ◽  
pp. 635-675 ◽  
Keyword(s):  
Simple Model ◽  
Impact Parameter ◽  
Water Drop ◽  
Free Fall ◽  
Electrostatic Energy ◽  
Good Effect ◽  
Frequency Distributions ◽  
Input Parameters ◽  
The Impact ◽  
Drop Charge

An experiment is described in which pairs of water drops of different size were caused to collide during free fall at a velocity equal to the difference of their terminal velocities in still air. The collision parameters of trajectory, drop size, and drop charge were controlled with precision, and impacts of a particular kind could be reproduced indefinitely. By using synchronized flash photography, well in excess of 30000 measurements were taken from more than 10000 frames of film of the resulting behaviour of the water-drop pairs. Data are discussed in terms of an impact parameter, X which defines the relative trajectory of the drops in the centre-of-mass frame, and three energy parameters e C , e R and e T which delineate the properties electrostatic energy, rotational energy, and total energy of the two-drop system before impact. Input parameters were confined to values appropriate to natural rainfall. After collision four basic types of rotation occurred, the particular kind of rotation depending upon X , e C , e R and e T . Measured rates of rotation were compared with that to be expected from a simple model of inelastic collision between solid spheres and showed a marked resemblance. Distributions of mass after collision were compared with a model based upon a bimodal Gaussian distribution to good effect. In addition, frequency distributions of the number of drop products resulting from a given collision were prepared showing the controlling influence of the impact parameter, X , and the effect of varying drop charge. Relations were also established between statistical values for the coalescence efficiency of a given drop pair and the input parameters; however, while all results were consistent and reproducible, the effect of drop charge could not be demonstrated by a simple model.

Experimental Investigation on Improving Electromechanical Impedance Based Damage Detection by Temperature Compensation

2013 ◽  
Vol 569-570 ◽  
pp. 1132-1139 ◽  
Author(s):  
Thomas Siebel ◽  
Mihail Lilov
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Temperature Compensation ◽  
Impact Damage ◽  
Correlation Coefficients ◽  
Electromechanical Impedance ◽  
Reinforced Plastic ◽  
Influence Of Temperature On ◽  
Compensation Approach ◽  
The Impact

The sensitivity of the electromechanical impedance to structural damage under varying temperature is investigated in this paper. An approach based on maximizing cross-correlation coefficients is used to compensate temperature effects. The experiments are carried out on an air plane conform carbon fiber reinforced plastic (CFRP) panel (500mm x 500mm x 5mm) instrumented with 26 piezoelectric transducers of two different sizes. In a first step, the panel is stepwise subjected to temperatures between-50 °C and 100 °C. The influence of varying temperatures on the measured impedances and the capability of the temperature compensation approach are analyzed. Next, the sensitivity to a 200 J impact damage is analyzed and it is set in relation to the influence of a temperature change. It becomes apparent the impact of the transducer size and location on the quality of the damage detection. The results further indicate a significant influence of temperature on the measured spectra. However, applying the temperature compensation algorithm can reduce the temperature effect at the same time increasing the transducer sensitivity within its measuring area. The paper concludes with a discussion about the trade-off between the sensing area, where damage should be detected, and the temperature range, in which damage within this area can reliably be detected.

A New Cam-follower Safety Joint Mechanism Design based on Variable-length Four-bar Linkage for Robot Safety

2021 ◽  
pp. 1-24
Author(s):  
Seung Guk Baek ◽  
Hyungpil Moon ◽  
Hyouk Ryeol Choi ◽  
Ja Choon Koo
Keyword(s):  
Load Transfer ◽  
Impact Damage ◽  
Surface Profile ◽  
Length Change ◽  
Variable Length ◽  
Core Element ◽  
Nonlinear Load ◽  
Cam Follower ◽  
Joint Mechanism ◽  
The Impact

Abstract Humans come into physical contacts with various machines such as robots in daily life. This leads to the underlying issue of guaranteeing safety during such human-robot interactions. Thus, many devices and methods have been studied for impact damage reduction. A safety joint mechanism (SJM) using four-bar linkages has been highlighted as an impact cutoff device owing to its capabilities of nonlinear load transfer. This paper focuses on a new design and testing for a kinematic element of an SJM based on four-bar linkages to improve the impact cutoff performances. In the present work, a set of variable-length floating link designs is proposed, and the mechanism is implemented by mechanical contact surface profile shaping between the cams and followers. The performance of the cam-follower mechanism is evaluated depending on the variable length of the floating link, by using equivalent stiffness method, which successfully quantifies the performance of the proposed mechanism. Based on this design and analysis, two SJMs having symmetrical arrangements for four numbers of cam-follower mechanisms are fabricated: one SJM has fixed-length floating links and the other has variable-length floating links. The effect of the new kinematic elements on the performance improvement is verified by comparing the absorbed impact rates of the two SJMs by impact hammer-like drop tests. Consequently, it is confirmed that the rapid length change of the floating link is the core element for improving the performance of the safety mechanism.

Impact of a Fixed-Length Rigid Cylinder on an Elastic-Plastic Homogeneous Body

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Raja R. Katta ◽  
Andreas A. Polycarpou
Keyword(s):  
Impact Damage ◽  
Element Model ◽  
Elastic Behavior ◽  
Magnetic Storage ◽  
Practical Case ◽  
Homogeneous Body ◽  
Rigid Cylinder ◽  
Elastic Plastic ◽  
Fixed Length ◽  
The Impact

A contact mechanics (CM) based model of a fixed-length rigid cylinder impacting a homogeneous elastic-plastic homogeneous body was developed and includes an improved method of estimating the residual depth after impact. The nonlinear elastic behavior during unloading was accounted for to develop an improved coefficient of restitution model. The impact model was applied to study a practical case of a cylindrical feature on the slider of a magnetic storage hard disk drive impacting the disk to predict various critical impact contact parameters. The CM model was validated using a plane strain finite element model and it was found that a cylindrical feature with a longer length results in a substantial alleviation of impact damage.

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