Transient dynamics model and 3D-DIC analysis of new-candidate for JEDEC JESD22-B111 test board

Failure analysis of a frangible composite cover: A transient-dynamics study

Journal of Composite Materials ◽

10.1177/0021998316673223 ◽

2016 ◽

Vol 51 (18) ◽

pp. 2607-2617

Author(s):

Deng’an Cai ◽

Guangming Zhou ◽

Yuan Qian ◽

Vadim V Silberschmidt

Keyword(s):

Finite Element ◽

Failure Analysis ◽

Failure Criterion ◽

Element Model ◽

Transient Dynamics ◽

Dynamics Model ◽

Test Device ◽

Weak Zone ◽

Failure Pressure ◽

Model Failure

A transient-dynamics model based on the approximate Riemann algorithm is proposed for the failure analysis of a frangible composite canister cover. The frangible cover, manufactured with a traditional manual lay-up method, is designed to conduct a simulated missile launch test using a specially developed test device. Deformation of the cover’s centre is determined using a transient-dynamics finite element model; failure pressure for the frangible cover is obtained based on a failure criterion and compared with simulated experimental results. Weak-zone position of the frangible cover has a significant effect on failure pressure compared to that of deformation of the cover’s centre. With the same structure of the weak-zone, an increase in its height can first raise and then reduce the level of failure pressure of the frangible cover. Close agreements between the experimental and numerical results are observed.

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Automotive dry clutch fully coupled transient tribodynamics

Nonlinear Dynamics ◽

10.1007/s11071-021-06605-x ◽

2021 ◽

Author(s):

I. Minas ◽

N. Morris ◽

S. Theodossiades ◽

M. O’Mahony ◽

J. Voveris

Keyword(s):

Transient Dynamics ◽

Dynamics Model ◽

Input Shaft ◽

Frictional Properties ◽

Clutch System ◽

Numerical Tool ◽

Dry Clutch ◽

Noise Vibration ◽

The Stability ◽

Fully Coupled

AbstractDetermining the root causes of Noise, Vibration and Harshness (NVH) phenomena in modern automotive drivetrains is a task of critical importance. This research investigates the stability of dry clutch systems vibrational behaviour during engagement. A fully coupled dry clutch numerical model including the influence of friction is presented and validated using vehicle measurements. The clutch component frictional properties are measured using parts that exhibit aggressive NVH behaviour using representative tribometric experiments. The validated numerical tool highlights the occurrence of instabilities which are caused by modal couplings, particularly between the input shaft bending and clutch disc radial motions. Such a validated transient dynamics model of a dry clutch system has not hitherto been presented in the open literature.

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Simulating Drillstring Dynamics Motion and Post-Buckling State with Advanced Transient Dynamics Model

SPE Drilling & Completion ◽

10.2118/199557-pa ◽

2021 ◽

pp. 1-15

Author(s):

Wei Chen ◽

Yuelin Shen ◽

Rongbing Chen ◽

Zhengxin Zhang ◽

Sheldon Andre Rawlins

Keyword(s):

Transient Dynamics ◽

Primary Concern ◽

Strong Nonlinearity ◽

Dynamics Model ◽

Friction Forces ◽

Weight On Bit ◽

Dynamics Simulations ◽

Improve Rate ◽

Wear Tool ◽

Helical Buckling

Summary As drilling sections become deeper and longer, transferring more weight downhole to improve rate of penetration is the primary concern for the operator. Drillstring dynamics and buckling are some primary limiters for drilling efficiency. Aggressive drilling parameters may lead to severe downhole dynamics, which leads to cutter breakage and tool damage. When axial compression exceeds a certain threshold, the drillstring buckles sinusoidally inside the wellbore first, followed by helical buckling. Buckling leads to accelerated joint wear, tool fatigue failures, and lower drilling efficiency. To better manage drillstring dynamics and buckling, we propose a method of simulating drillstring dynamics motion and postbuckling state using an advanced transient dynamics model. An analysis methodology was developed on the basis of the finite element transient dynamics model. The model captures the enriched physics of drillstring dynamics and loading: the large deformation of buckled drillstring, the strong nonlinearity of contact and friction forces, and the dynamically triggered instability caused by drilling rotation. Transient dynamics simulations are conducted for drillstring with the actual well trajectory and rotation speed. The weight on bit (WOB) is ramped up gradually, and the drillstring deformation is monitored to detect the onset of buckling or dynamics instability. To conduct the model validation, the buckling inception loads predicted by the model are compared against the analytical equation of critical buckling loads. A field extended reach drilling (ERD) job was simulated by the model. The downhole weight and torque data from the measurement-while-drilling (MWD) tool was used to validate the weight transfer prediction by the model. Most existing buckling theories use the analytical equations of critical buckling load, which were normally derived on the basis of the idealized assumptions, such as perfect wellbore shape and uniform tubular geometry. The proposed method simulates the drillstring behaviors in the field drilling conditions and aims to capture effects of wellbore friction and string rotation. The transient dynamics model is capable of simulating drillstring dynamics movement (whirling and snaking) and weight lockup under severe helical buckling. An automatic method is proposed to interpret the drillstring behaviors from the simulation results. Using the transient dynamics model, the procedure presented in this article can simulate the dynamics and buckling behaviors of drillstring and help mitigate associated risks in well-planning and execution phases.

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