Effect of Multimaterial Layering on the Response of a Generic Hull Structure

1997 ◽  
Author(s):  
Aaron D. Gupta ◽  
Christopher Meyer
Keyword(s):  
Dynamic Response ◽  
Support System ◽  
Comparative Evaluation ◽  
Single Layer ◽  
Circular Opening ◽  
Vibrational Response ◽  
Multilayered Composite ◽  
Modal Response ◽  
Hull Structure ◽  
Composite Armor

Abstract The dynamic response of a basic, generic, multilayered, composite vehicle hull with a large, circular opening for the turret assembly has been compared with that of an equivalent single-layer, basic metallic hull with identical geometry to assess the influence of a multilayered, composite armor panel structure on the modal response. Both models, without the engine block, mountings, transmission, and base support system consisting of tracks, wheels, sprockets, torsion bars, etc., were generated using PATRAN 3 to facilitate computational modal analysis and comparative evaluation of the influence of multilayered construction on the free vibrational response.

Dynamic Response Analysis of Butt Joint of HTS-A Steel Considering Welding Residual Stresses

2013 ◽  
Vol 423-426 ◽  
pp. 944-950
Author(s):  
Wei Shen ◽  
Ren Jun Yan ◽  
Lin Xu ◽  
Kai Qin ◽  
Xin Yu Zhang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Dynamic Response ◽  
Hot Spot ◽  
Time History ◽  
High Strength ◽  
Simulation Method ◽  
Butt Joint ◽  
Welding Residual Stress ◽  
Response Analysis ◽  
Hull Structure

This paper uses both numerical simulation method and experimental research method to study on welding residual stress of high-strength steel of the cone-cylinder hull. Welding is often accompanied by a larger welding residual stress, which directly affects the safety and service life of the hull structure. In order to obtain the distribution of the welding residual stress, the welding procedure was developed by its parameter language by using FE analysis software in this paper. Then the welding residual stress of hot spot region was measured through X-ray nondestructive testing method, and compared it with simulation results. Finally, considering the residual stress as the initial stress, this paper analyzed dynamic response process of the welding structure under combined actions of the welding residual stress and multiaxial loads, which could more accurately determine the stress of welding structure and the location of fatigue risk point. According to the amplitude of damage parameters and strain time-history curve, we can estimate the fatigue life of structure by selecting the corresponding damage models.

3-D elastic coupling vibration and acoustical radiation characteristics of cracked gear under elastic support condition

2015 ◽  
Vol 23 (9) ◽  
pp. 1548-1568 ◽  
Author(s):  
Shao Renping ◽  
Purong Jia ◽  
Xiankun Qi
Keyword(s):  
Dynamic Response ◽  
Support System ◽  
Three Dimensional ◽  
Elastic Support ◽  
Dynamic Responses ◽  
Tooth Root ◽  
Support Condition ◽  
Elastic Boundary ◽  
Root Crack ◽  
Elastic Disc

According to the actual working condition of the gear, the supporting gear shaft is treated as an elastic support. Its impact on the gear body vibration is considered and investigated and the dynamic response of elastic teeth and gear body is analyzed. On this basis, the gear body is considered as a three-dimensional elastic disc and the gear teeth are treated as an elastic cantilever beam. Under the conditions of the elastic boundary (support shaft), combining to the elastic disk and elastic teeth, the influence of three-dimensional elastic discs on the meshing tooth response under an elastic boundary condition is also included. A dynamic model of the gear support system and calculated model of the gear tooth response are then established. The inherent characteristics of the gear support system and dynamics response of the meshing tooth are presented and simulated. It was shown by the results that it is correct to use the elastic support condition to analyze the gear support system. Based on the above three-dimensional elastic dynamics analysis, this paper set up a dynamics coupling model of a cracked gear structure support system that considered the influence of a three-dimensional elastic disc on a cracked meshing tooth under elastic conditions. It discusses the dynamic characteristic of the cracked gear structure system and coupling dynamic response of the meshing tooth, offering a three-dimensional elastic body model of the tooth root crack and pitch circle crack with different sizes, conducting the three-dimensional elastic dynamic analysis to the faulty crack. ANSYS was employed to carry out dynamic responses, as well as to simulate the acoustic field radiation orientation of a three-dimensional elastic crack body at the tooth root crack and pitch circle with different sizes.

Comparative Evaluation of Compacting Process for Base Materials using Lab Compaction Methods

2019 ◽  
Vol 2673 (4) ◽  
pp. 558-567 ◽  
Author(s):  
Xiaoyang Jia ◽  
Wei Hu ◽  
Pawel Polaczyk ◽  
Hongren Gong ◽  
Baoshan Huang
Keyword(s):  
Dynamic Response ◽  
Laboratory Testing ◽  
Comparative Evaluation ◽  
Laboratory Scale ◽  
Dynamic Responses ◽  
Comparative Experiment ◽  
Base Materials ◽  
Superpave Gyratory Compactor ◽  
Precise Characterization

Precise characterization of the compactability of aggregates and soils in the laboratory has always been a challenge to pavement technologists. The present study investigated compactability of aggregates and soils through the comparison of three laboratory compaction methods, the Superpave Gyratory Compactor, the Marshall impacting hammer, and a vibratory compacting machine. Accelerometers were attached to the Marshall impacting hammer and a laboratory scale vibratory compactor to capture the dynamic response of soils and aggregates during compaction. The results from this comparative experiment indicated that there was a consistent relationship between the stiffness of soils and aggregates and the dynamic responses from impaction and vibration, which can be used to better characterize the compactability of different paving materials through laboratory testing.

Dynamic Stress Analysis of Multilayered Structure With Radial Gaps of Cylindrical Pressure Vessel Under Plane Strain Conditions

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Huadong Liu ◽  
Weiqiang Wang
Keyword(s):  
Plastic Deformation ◽  
Dynamic Response ◽  
Plane Strain ◽  
Pressure Vessel ◽  
Single Layer ◽  
Multilayered Structure ◽  
Multilayered Structures ◽  
Loading Process ◽  
Cylindrical Pressure Vessel ◽  
Gap Height

Radial gaps were found in multilayered cylindrical vessels which experience inner explosion accidents in chemical plants in the past few years worldwide. It is necessary to investigate the dynamic response of multilayered structures with radial gaps to ensure the vessel safety. This paper presented a numerical modeling of the dynamic response of a multilayered structure with radial gaps of cylindrical pressure vessel under plane strain conditions by using the ANSYS/ls-dyna package. The effects of the dynamic loading profile and the radial gap height are considered in the investigation. The stress spatial distribution, the stress and the plastic deformation variation curves with time are emphatically analyzed. The results show that the stress variation of the entire loading process can be divided into four stages: the oscillation stage, the yield stage, the fast increase stage, and the redistribution stage. The layer stress distributes discontinuously at the gaps between layers and distributes unevenly in any single layer. The inner layer stress is not always larger than the outer layers' during the whole loading process. The effect of loading profile on the dynamic response is not as obvious as the gap height. As the gap height increases, the stress oscillation stage is suppressed and becomes shorter. While the loading recovers to the operation pressure, the stress and the plastic deformation of inner layers increases and vice versa for the outer layers.

Three-Dimensional Analysis of Cracking in a Multilayered Composite

1995 ◽  
Vol 62 (2) ◽  
pp. 273-281 ◽  
Author(s):  
C. H. Kuo ◽  
L. M. Keer
Keyword(s):  
Integral Equations ◽  
Stiffness Matrix ◽  
Crack Opening ◽  
Crack Problem ◽  
Three Dimensional ◽  
Single Layer ◽  
Singular Integral Equations ◽  
Material System ◽  
Multilayered Composite ◽  
Penny Shaped Crack

The three-dimensional problem of a multilayered composite containing an arbitrarily oriented crack is considered in this paper. The crack problem is analyzed by the equivalent body force method, which reduces the problem to a set of singular integral equations. To compute the kernels of the integral equations, the stiffness matrix for the layered medium is formulated in the Hankel transformed domain. The transformed components of the Green’s functions and derivatives are determined by solving the stiffness matrix equations, and the kernels are evaluated by performing the inverse Hankel transform. The crack-opening displacements and the three modes of the stress intensity factor at the crack front are obtained by numerically solving the integral equations. Examples are given for a penny-shaped crack in a bimaterial and a three-material system, and for a semicircular crack in a single layer adhered to an elastic half-space.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Impact Load ◽  
Residual Deformation ◽  
Time History ◽  
Single Layer ◽  
Element Analysis ◽  
Deformation Stage ◽  
The Impact

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

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