Mechanical Event Simulation of Drop Testing for Toy Product

2006 ◽  
Vol 532-533 ◽  
pp. 993-996
Author(s):  
Anthony Yee Kai Yam ◽  
Kai Leung Yung ◽  
Chi Wo Lam
Keyword(s):  
Material Properties ◽  
Impact Analysis ◽  
Plastic Material ◽  
Free Fall ◽  
Drop Impact ◽  
Local Analysis ◽  
Element Analysis ◽  
Event Simulation ◽  
Long Time ◽  
The Impact

Toys that are free from drop failures normally take a long time to develop. It is often time and cost consuming after the production tooling is built to detect drop test failure. This paper introduces a new drop testing analysis method for Toys. The method uses a simple approach with a local analysis that based on the linear and non linear finite element analysis. Modeling and transient drop analysis of a pre-school toy is used as a case study to demonstrate the method. The impact analysis of the product hitting the solid concrete floor after a free fall is presented. The analysis focuses on the deformation of the housing for a product with electronic circuit and mechanical mechanism inside. Experimental data has been obtained for drop simulation of the housing and its correlation with the plastic material properties. The stress and strain of the housing during drop impact tests are noted. The effects of the material properties to the housing deflection under drop/impact shock have been investigated. Numerical results are compared with experimental results to validate the method.

The Impact Analysis of Ground Stability Caused by Exploiting Underground Coal

2011 ◽  
Vol 243-249 ◽  
pp. 3147-3150
Author(s):  
Shu Xian Liu ◽  
Xiao Gang Wei ◽  
Shu Hui Liu ◽  
Li Ping Lv
Keyword(s):  
Numerical Simulation ◽  
Coal Mining ◽  
Impact Analysis ◽  
Shear Failure ◽  
Failure Process ◽  
Wall Rock ◽  
Strong Impact ◽  
Element Analysis ◽  
Deformation And Failure ◽  
The Impact

Disaster caused by exploiting underground coal is due to original mechanical equilibrium of underground rock has been destroyed when underground coal is exploited. And Stress redistribution and stress concentration of wall rock in the goaf happened too. As many complex factors exist such as complex structures of ground, multivariate stope boundary conditions, many stochastic mining factors and so on, it is difficult to evaluate the damage of the geological environment caused the excavation by surrounding underground coal accurately. Besides that, the coexistence of continuous and discontinuous of deformation and failure of wall rock make a strong impact on the ground, and the co-exist of tension, compression and shear failure also pay a great deal contribution to the destroy. Due to the mechanical property and deformation mechanism of goaf are complex , changeable, nonlinear and probabilistic, which changes with in space and time dynamically, it can not be studied analytically by the classical mathematical model and the theory of mechanics computation. Through finite element analysis software ABAQUS, a numerical simulation of the process of underground coal mining have been made. After make a research of the simulation process, it shows the change process of stress environment of wall rock and deformation and failure process of rock mass during the process of coal mining. The numerical simulation of the process can provide theoretical basis and technical support to the protection and reinforcement of laneway the process of coal excavation. Besides that, it also provides a scientific basis and has a great significance to reasonable Excavation and control of mind-out area.

Dropped Object Impact Analysis of Subsea Tree Frame

2014 ◽  
Author(s):  
Kumarswamy Karpanan ◽  
Craig Hamilton-Smith
Keyword(s):  
Impact Analysis ◽  
Oil And Gas ◽  
Terminal Velocity ◽  
Gas Production ◽  
Element Analysis ◽  
Oil And Gas Production ◽  
Operational Life ◽  
Critical Components ◽  
Electrical Components ◽  
The Impact

Subsea oil and gas production involves assemblies such as trees, manifolds, and pipelines that are installed on sea floor. Each of these components is exposed to severe working conditions throughout its operational life and is difficult and expensive to repair or retrieve installed. During installation and operation, a rig/platform and several supply vessels are stationed on the waterline directly above the well and installed equipment below. If any object is to be dropped overboard, it presents a hazard to the installed equipment. A subsea tree comprises of a number of critical components such as valves and hydraulic actuators, in addition to several electrical components such as the subsea control module and pressure/temperature gauges. Their ability to operate correctly is vital to the safe production of oil and gas. If an object were to impact and damage these components, resulting in their inability to operate as intended, the consequences could be severe. In this paper, a typical subsea tree frame is analyzed to ensure its ability to withstand the impact from an object accidentally dropped overboard. This was accomplished using nonlinear dynamic Finite Element Analysis (FEA). In this study, the framework was struck by a rigid body at terminal velocity, resulting in a given impact energy. Displacements and resultant strain values at critical locations were then compared to allowable limits to ensure compliance to the design requirements.

scholarly journals A coupled stochastic rainfall-evapotranspiration model for hydrological impact analysis

2017 ◽  
Author(s):  
Minh Tu Pham ◽  
Hilde Vernieuwe ◽  
Bernard De Baets ◽  
Niko E. C. Verhoest
Keyword(s):  
Time Series ◽  
Impact Analysis ◽  
Hydrological Model ◽  
Hydrological Cycle ◽  
Rainfall Runoff ◽  
Hydrological Impact ◽  
Long Time ◽  
Rainfall Runoff Model ◽  
The Impact ◽  
Runoff Model

Abstract. A hydrological impact analysis concerns the study of the consequences of certain scenarios on one or more variables or fluxes in the hydrological cycle. In such exercise, discharge is often considered, as especially extreme high discharges often cause damage due to the coinciding floods. Investigating extreme discharges generally requires long time series of precipitation and evapotranspiration that are used to force a rainfall-runoff model. However, such kind of data may not be available and one should resort to stochastically-generated time series, even though the impact of using such data on the overall discharge, and especially on the extreme discharge events is not well studied. In this paper, stochastically-generated rainfall and coinciding evapotranspiration time series are used to force a simple conceptual hydrological model. The results obtained are comparable to the modelled discharge using observed forcing data. Yet, uncertainties in the modelled discharge increase with an increasing number of stochastically-generated time series used. Notwithstanding this finding, it can be concluded that using a coupled stochastic rainfall-evapotranspiration model has a large potential for hydrological impact analysis.

scholarly journals 2-Step Drop Impact Analysis of a Miniature Mobile Haptic Actuator Considering High Strain Rate and Damping Effects

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 272 ◽  
Author(s):  
Choi ◽  
Choi ◽  
Kang ◽  
Jeon ◽  
Lee
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Impact Analysis ◽  
High Strain ◽  
Drop Impact ◽  
Tactile Feedback ◽  
Smart Device ◽  
Damping Effects ◽  
Impact Characteristics ◽  
The Impact

In recent times, the haptic actuators have been providing users with tactile feedback via vibration for a realistic experience. The vibration spring must be designed thin and small to use a haptic actuator in a smart device. Therefore, considerable interests have been exhibited with respect to the impact characteristics of these springs. However, these springs have been difficult to analyze due to their small size. In this study, drop impact experiments and analyses were performed to examine the damages of the mechanical spring in a miniature haptic actuator. Finally, an analytical model with high strain rate and damping effects was constructed to analyze the impact characteristics.

scholarly journals A coupled stochastic rainfall–evapotranspiration model for hydrological impact analysis

2018 ◽  
Vol 22 (2) ◽  
pp. 1263-1283 ◽  
Author(s):  
Minh Tu Pham ◽  
Hilde Vernieuwe ◽  
Bernard De Baets ◽  
Niko E. C. Verhoest
Keyword(s):  
Time Series ◽  
Impact Analysis ◽  
Hydrological Cycle ◽  
Rainfall Runoff ◽  
Hydrological Impact ◽  
Long Time ◽  
Rainfall Runoff Model ◽  
The Impact ◽  
Vine Copulas ◽  
Runoff Model

Abstract. A hydrological impact analysis concerns the study of the consequences of certain scenarios on one or more variables or fluxes in the hydrological cycle. In such an exercise, discharge is often considered, as floods originating from extremely high discharges often cause damage. Investigating the impact of extreme discharges generally requires long time series of precipitation and evapotranspiration to be used to force a rainfall-runoff model. However, such kinds of data may not be available and one should resort to stochastically generated time series, even though the impact of using such data on the overall discharge, and especially on the extreme discharge events, is not well studied. In this paper, stochastically generated rainfall and corresponding evapotranspiration time series, generated by means of vine copulas, are used to force a simple conceptual hydrological model. The results obtained are comparable to the modelled discharge using observed forcing data. Yet, uncertainties in the modelled discharge increase with an increasing number of stochastically generated time series used. Notwithstanding this finding, it can be concluded that using a coupled stochastic rainfall–evapotranspiration model has great potential for hydrological impact analysis.

scholarly journals Drop Impact on Textile Material: Effect of Fabric Properties

2014 ◽  
Vol 14 (3) ◽  
pp. 145-151 ◽  
Author(s):  
Zouhaier Romdhani ◽  
Ayda Baffoun ◽  
Mohamed Hamdaoui ◽  
Sadok Roudesli
Keyword(s):  
Water Drop ◽  
Free Fall ◽  
Spreading Rate ◽  
Drop Impact ◽  
Drop Deformation ◽  
Coating Film ◽  
Drop Shape ◽  
Coated Fabric ◽  
Fabric Construction ◽  
The Impact

Abstract This paper presents an experimental study of impact of water drop on a surface in a spreading regime with no splashing. Three surfaces were studied: virgin glass, coating film and woven cotton fabric at different construction parameters. All experiments were carried out using water drop with the same free fall high. Digidrop with high-resolution camera is used to measure the different parameters characterising this phenomenon. Results show an important effect of the height of the free fall on the drop profile and the spreading behaviour. An important drop deformation at the surface impact was observed. Then, fabric construction as the weft count deeply affects the drop impact. For plain weave, an increase of weft count causes a decrease in penetration and increase in the spreading rate. The same result was obtained for coated fabric. Therefore, the impact energy was modified and the drop shape was affected, which directly influenced the spreading rate.

Effect of Corner Staking on the Fatigue Life of BGA Under Thermal Cycling

2017 ◽  
Author(s):  
Deng Yun Chen ◽  
Michael Osterman
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Material Properties ◽  
Solder Joints ◽  
Material Selection ◽  
Temperature Cycling ◽  
Sac305 Solder ◽  
Element Analysis ◽  
Bga Packages ◽  
The Impact

Solder interconnects in electronic assemblies are susceptible to failures due to environmental high strain rate impact and cyclic stresses. To mitigate the failures, adhesive bonds can be added after the solder assembly process to provide additional mechanical support. For ball grid array (BGA) packages, the adhesive is normally applied to the corners of the package and referred to as corner staking. In addition to corner staking, underfill is also a strategy used to mitigate the stresses on the solder joints. While components with underfill has been widely studied, the study of the impact of corner staking on the reliability of packages remains limited. This paper presents a study of corner-staked BGA packages with tin-3.0 silver-0.5 copper (SAC305) solder subjected to temperature cycling. Experimental temperature cycling is conducted to examine impact of the selected corner staking material on the fatigue life of BGAs. Further, finite element analysis is conducted to understand the influence of material properties of staking material on the fatigue life of BGAs. The result of the study indicates that the presence of corner staking, with selected material properties, reduces the damage on the solder joints under thermal cycling, and thus increases its fatigue life by about 80%. This paper may serve as a guidance for staking material selection to improve the fatigue life of solder joints of BGAs under thermal cycling.

Evaluation of macro finite elements for use in global/local analysis of textile composites

2011 ◽  
Vol 46 (9) ◽  
pp. 1111-1125 ◽  
Author(s):  
Kevin S Maxwell ◽  
John D Whitcomb
Keyword(s):  
Finite Element Analysis ◽  
Material Properties ◽  
Textile Composites ◽  
Local Analysis ◽  
Element Analysis ◽  
Global Response ◽  
Material Inhomogeneity ◽  
Macro Elements ◽  
Local Methods ◽  
Single Field

Textile composites are ideal candidates for global/local finite element analysis because the global response of composites is so dependent on the complex microstructure of the weave. However, most global/local methods use homogenization to approximate the global material properties, which results in loss of information about material architecture. In this work, single field and multi-field macro-elements were used to account for material inhomogeneity within each element in the global region. The effectiveness of these macro-elements vs. using homogenized properties was evaluated for several configurations. It was found that using macro-elements in the global region of a model generally yields greater accuracy than using homogenized properties.

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