On the Effect of Shear on Plastic Deformation of Beams Under Transverse Impact Loading

1960 ◽  
Vol 27 (1) ◽  
pp. 107-110 ◽  
Author(s):  
B. Karunes ◽  
E. T. Onat
Keyword(s):  
Impact Loading ◽  
Pure Shear ◽  
Bending Moment ◽  
Transverse Impact ◽  
Rigid Plastic ◽  
Inertia Effects ◽  
Interaction Diagram ◽  
Shear Effects ◽  
The Impact ◽  
Special Case

The impact problem for a rigid-plastic beam is formulated by using an interaction curve relating shearing force and bending moment for fully plastic action, and allowing for shear and rotary inertia effects. Using a simplified interaction diagram, the problem of point-impact loading is solved for a special case. The analysis shows that the shear effects are of considerable importance when the parameter μ0 = 2Q0l/M0 is less than 20 where Q0 and M0 are plastic-carrying capacities of the cross section for pure shear and bending, respectively, and 21 is the length of the beam.

scholarly journals Collapse Behaviour of a Concrete-Filled Steel Tubular Column Steel Beam Frame under Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lian Song ◽  
Hao Hu ◽  
Jian He ◽  
Xu Chen ◽  
Xi Tu
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Mechanical Performance ◽  
Impact Load ◽  
Frame Structure ◽  
Actual Condition ◽  
Transverse Impact ◽  
Time Curve ◽  
Finite Element Software ◽  
The Impact

The progressive collapse of a concrete-filled steel tubular (CFST) frame structure is studied subjected to impact loading of vehicle by the finite-element software ABAQUS, in the direct simulation method (DS) and alternate path method (AP), respectively. Firstly, a total of 14 reference specimens including 8 hollow steel tubes and 6 CFST specimens were numerically simulated under transverse impact loading for verification of finite-element models, which were compared with the existing test results, confirming the overall similarity between them. Secondly, a finite-element analysis (FEA) model is established to predict the impact behaviour of a five-storey and three-span composite frame which was composed of CFST columns and steel beams under impact vehicle loading. The failure mode, internal force-time curve, displacement-time curve, and mechanical performance of the CFST frame were obtained through analyzing. Finally, it is concluded that the result by the DS method is closer to the actual condition and the collapse process of the structure under impact load can be relatively accurately described; however, the AP method is not.

Inelastic failure of fully clamped beams and circular plates under impact loading

2002 ◽  
Vol 216 (2) ◽  
pp. 133-149 ◽  
Author(s):  
N Jones ◽  
C Jones
Keyword(s):  
Impact Loading ◽  
Elementary Theory ◽  
Threshold Energy ◽  
Steel Beams ◽  
Circular Plates ◽  
Rigid Plastic ◽  
Threshold Conditions ◽  
Clamped Beams ◽  
Impact Energies ◽  
The Impact

An experimental investigation is reported on the impact loading of fully clamped mild steel beams and circular plates struck by relatively heavy masses. The impact energies are sufficient in some tests to cause material failure and, thus, to provide the threshold conditions for cracking and severance for impact velocities up to 6.74m/s for beams and 15.66m/s for plates. The beams were struck at several locations across the span, and a significant reduction in the threshold energy is observed for strikes near to a support. Round-nosed impactors require more energy to induce failures than flat-nosed ones. Furthermore, they cause failure to develop at the supports of both beams and plates rather than initiating rupture at the impact point, which is the case for a blunt striker. Reasonable agreement is obtained between the predictions of an elementary theory, which uses rigid-plastic methods of analysis, and the experimental results for the deflection and failure of beams struck at the mid-span. The experimental data, which include static and dynamic material properties, are suitable for calibrating numerical schemes and for further study on the accuracy of criteria for the dynamic inelastic failure of structures.

Plastic Deformation of Semi-Infinite Beams Subject to Transverse Impact Loading at the Free End

1956 ◽  
Vol 23 (2) ◽  
pp. 239-243
Author(s):  
M. F. Conroy
Keyword(s):  
Plastic Deformation ◽  
Impact Loading ◽  
Constant Velocity ◽  
Bending Moment ◽  
Transverse Force ◽  
Square Root ◽  
Transverse Loading ◽  
Transverse Impact ◽  
Velocity Impact ◽  
Time Part

Abstract The object of this paper is to consider the plastic deformation of semi-infinite beams subject to dynamic transverse loading at the free end. The type of loading considered is that of a constant bending moment, together with a transverse force the magnitude of which is inversely proportional to the square root of time. Part 1 of the paper consists of a plastic-rigid analysis of the problem, based on the plastic-rigid analysis of infinite beams under transverse, constant velocity, impact loading developed by the author. Part 2 of the paper consists of an elastic-plastic solution of the problem, based on a theoretical analysis of the plastic deformation of infinite beams subject to transverse, constant-velocity impact loading developed by H. F. Bohnenblust. Specific problems are considered for which the deflection solutions obtained by elastic ideally plastic and rigid ideally plastic analyses are compared.

Plastic-Rigid Analysis of Long Beams Under Transverse Impact Loading

1952 ◽  
Vol 19 (4) ◽  
pp. 465-470
Author(s):  
M. F. Conroy
Keyword(s):  
Impact Loading ◽  
Bending Moment ◽  
Large Strains ◽  
Transverse Impact ◽  
Plastic Bending ◽  
Elastic Plastic ◽  
Straight Line ◽  
Probable Form ◽  
Constant Yield ◽  
Elastic Strains

Abstract The object of this paper is to set forth the results of an investigation of the behavior of long beams under transverse, constant-velocity impact loading, when a plastic-rigid type of analysis is adopted. It was expected that such an analysis would be satisfactory for problems involving large strains, and easier to evaluate than the corresponding elastic-plastic solution. Consideration is first given to the case of ideal plasticity. Elastic strains are neglected and the material of the beam is assumed to flow plastically at a constant yield limit. In this case expressions for the bending moment, shear force, curvature and deflection distributions along the beam are obtained analytically for any given impact velocity. The manner in which the solution for a beam having an elastic-ideally plastic bending moment-curvature relationship converges to the plastic-rigid solution, as EI increases, is discussed. Consideration is next given to the case of work-hardening where the material is assumed to obey a plastic-rigid bending moment-curvature relationship consisting of a straight line with nonzero slope. Unfortunately, difficulty arises in finding a solution analytically in this case. However, by considering the solution for a beam having the corresponding elastic-plastic bending moment-curvature relationship and a large EI-value, some speculation as to the probable form of the solution may be made.

Impact of a Nonlinear Viscoplastic Rod on a Rigid Wall

1966 ◽  
Vol 33 (3) ◽  
pp. 505-513 ◽  
Author(s):  
T. C. E. Ting
Keyword(s):  
Strain Rate ◽  
Power Law ◽  
Rigid Wall ◽  
The Other ◽  
Stress And Strain ◽  
Rigid Plastic ◽  
Residual Strains ◽  
Stress And Strain Rate ◽  
The Impact ◽  
Special Case

Barenblatt and Ishlinskii [5] considered the impact of a viscoplastic rod on a rigid wall in which the relation between stress and strain rate is linear. In this paper, their analysis is generalized to a power-law relation between stress and strain rate so that their results may be reduced as a special case. Some strikingly different behaviors are observed between linear viscoplastic materials and nonlinear viscoplastic materials. Comparisons are also made between the viscoplastic solution obtained here with the rate-independent, rigid-plastic solution by Lee and Tapper [2]. It is shown that the curves which represent the residual strains versus the axial length along the rod are concave upward for all viscoplastic rods. For the rate-independent, rigid-plastic rods, on the other hand, they are concave downward.

Dynamic Response Analysis for Rigid Steel Portal Frames under Impact Loading

2011 ◽  
Vol 82 ◽  
pp. 247-252
Author(s):  
Masato Komuro ◽  
Norimitsu Kishi ◽  
Yusuke Kurihashi ◽  
Wai Fah Chen
Keyword(s):  
Impact Loading ◽  
Three Dimensional ◽  
Bending Moment ◽  
Fe Analysis ◽  
Response Analysis ◽  
Maximum Displacement ◽  
Moment Distribution ◽  
Basic Understanding ◽  
Falling Weight ◽  
The Impact

In order to improve our basic understanding of the impact-resistant behavior of steelstructures, three-dimensional elasto-plastic FE analysis was conducted for steel portal framesunder impact loading. Here, two rigid portal frames of different column size were numericallyanalyzed taking the impact velocity of the falling weight as variable. The results obtained fromthis study are as follows: 1) maximum displacement of the frame increases linearly with eachincrement of the input impact energy; and 2) the bending moment distribution of the wholeframe at the time when the maximum response displacement occurs is similar to that understatic loading.

Evaluation of Impact Loads of Clutch Engaging Within Single Shaft Applications for Power Generation

2008 ◽  
Author(s):  
Bernd Lu¨neburg ◽  
Meinolf Klocke ◽  
Stefan Kulig ◽  
Frank Joswig
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Impact Loading ◽  
Power Plants ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Mass Model ◽  
Inertia Effects ◽  
The Impact

Combined Cycle Power Plants (CCPP) in single shaft arrangements consist of a gas turbine, a generator and a steam turbine on one shaft line. In order to enhance the plant availability and operational flexibility, Siemens Fossil Power Generation introduces a switchable clutch between steam turbine and generator. The clutch is a synchronous self-shifting device that engages automatically at rated speed as soon as the steam turbine overruns the gas turbine-generator. It disengages automatically when the steam turbine speed drops below the speed of the gas turbine. A rather complicated mechanism consisting pawls and ratchets and a thread of helical splines including damper mechanisms is used to provide the required coupling functions. The primary reason for the clutch is to ensure independent gas turbine and steam turbine operation below steam turbine rated speed. The clutch is especially advantageous during startup and gas turbine simple-cycle operation. Next to these advantages, the clutch engaging processes could introduce significant impact loading to the shaft components which differ from other. Next to the normal engaging process fault cases like engaging processes after gas turbine trip at high acceleration values due to the gas turbine compressor losses must be sustained by all rotor train components. This paper documents a nonlinear torsional analysis of the single shaft arrangement to assess the impact loading due to clutch engaging processes. A dynamic three-mass-model of the clutch including nonlinear stiffness and damping functions is set up and applied for the simulations. The coupling of the translatory and the rotatory inertia effects of the main sliding component of the clutch has been taken into account. Different load case scenarios in different single shaft component arrangements respectively different inertia ranges of the steam turbine rotor train are investigated in detail by the transient analyses. Based on this procedure, it is ensured that the mechanical layout of the single shaft components is sufficiently designed to withstand all operational loads under normal and faulty operating conditions.

scholarly journals THE EFFECT OF KNEE POSTURES AND CUSHIONS IN THE LOAD TRANSMISSION OF IMPACT LOADING - AN IN VITRO BIOMECHANICAL PORCINE MODEL

2004 ◽  
Vol 16 (04) ◽  
pp. 165-172
Author(s):  
JAW-LIN WANG ◽  
YEN-LIN LEE
Keyword(s):  
Knee Joint ◽  
Impact Loading ◽  
Shear Force ◽  
Mechanical Response ◽  
Impact Force ◽  
Reaction Force ◽  
Bending Moment ◽  
Shock Attenuation ◽  
Neutral Posture ◽  
The Impact

Degenerative osteoarthritis is the consequence of impact force applied to articular cartilage that results in surface fissuring. Soft cushions and flexed posture are two important factors to reduce the impact force; however, no quantitative information of how soft should the cushion be to prevent the injury and the mechanism of force attenuation of knee joint at neutral and flexed posture was not well documented yet. The objective of current study is hence to find the quantitative shock attenuation of knee joint using different stiffness of cushions when the knee is at neutral posture and flexed posture. A “drop-tower type” impact apparatus was used for testing. Nineteen fresh porcine knee joints were divided into two posture groups, i.e. neutral and flexed posture. All specimens were tested using stiff, medium, and soft cushions. The axial reaction force, anteroposterior shear force, and flexion bending moment were recorded for analysis. We found the flexed posture decreased the axial reaction force and anterior shear force but increased the flexion bending moment. The effect of stiffness of cushions on the mechanical response of knee joint during impact loading was significant for neutral posture but not for flexed posture.

Numerical and experimental study on effect of braiding angle on low-velocity transverse punch response of braided composite tube

2019 ◽  
Vol 29 (4) ◽  
pp. 667-686 ◽  
Author(s):  
Yeli Jin ◽  
Zhenyu Wu ◽  
Zhongxiang Pan ◽  
Laihu Peng ◽  
Xudong Hu
Keyword(s):  
Impact Loading ◽  
Failure Modes ◽  
Transverse Impact ◽  
Low Velocity ◽  
Composite Tubes ◽  
Braided Composite ◽  
Composite Tube ◽  
Damage Initiation ◽  
Braiding Angle ◽  
The Impact

In this study, the performance of braided composite tubes under low-velocity transverse impact loading at mid-span was investigated using both numerical and experimental methods. Three types of braided composite tubes with different braiding angles (30°, 45°, and 60°) were manufactured. The transverse punch behavior of the tubes was examined on a low-velocity imspact test bench. A meso-level finite element model of the composite tube was also established for identifying the damage initiation and development. The numerical results showed a good correlation with the experimental data. The mechanical response including force–time histories, force–displacement histories, and fracture morphologies was compared between three types of composite tubes for analyzing the influence of braiding angle on the impact response and failure mode. Although suffering from the low bending stiffness depends on fiber volume fraction at initial impact stage, the braided tube with 30° angle engaged more portion to resist impact loading in subsequent process and thus presented higher peak loading than the one with large angle. In addition, there are distinct different failure modes between composite tubes with various braiding angles. Shear yarn breakage underneath the punch was prone to occur in 30° sample because the braiding yarn was closer to the axial direction of tube. In contrast, the resin was deboned severely from the braiding yarn and then the braiding yarn exhibits plastic deformation in 60° sample due to the stress concentration caused by the large braiding angle.

Impact of Digitalization on Service Work in Knowledge-Intensive Business Services: An Empirical Study in Tax Consultancies

2019 ◽  
Vol 3 (4) ◽  
pp. 209-222
Author(s):  
Philipp K. Görs ◽  
Henning Hummert ◽  
Anne Traum ◽  
Friedemann W. Nerdinger
Keyword(s):  
Work Engagement ◽  
Service Work ◽  
Psychological Consequences ◽  
Business Services ◽  
Knowledge Intensive Business Services ◽  
Positive Effects ◽  
Knowledge Intensive ◽  
The Impact ◽  
Positive Effect ◽  
Special Case

Digitalization is a megatrend, but there is relatively little knowledge about its consequences for service work in general and specifically in knowledge-intensive business services (KIBS). We studied the impact of digitalization on psychological consequences for employees in tax consultancies as a special case of KIBS. We compare two tax consulting jobs with very different job demands, those of tax consultants (TCs) and assistant tax consultants (ATCs). The results show that the extent of digitalization at the workplace level for ATCs correlates significantly positively with their job satisfaction. For TCs, the same variable correlates positively with their work engagement. These positive effects of digitalization are mediated in the case of ATCs by the impact on important job characteristics. In the case of TCs, which already have very good working conditions, the impact is mediated by the positive effect on self-efficacy. Theoretical and practical consequences of these results are discussed.

Sign in / Sign up

Export Citation Format

Share Document