scholarly journals A Study of Support Characteristics of Collaborative Reinforce System of U-Steel Support and Anchored Cable for Roadway under High Dynamic Stress

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qizhou Wang ◽  
Haiwang Ye ◽  
Ning Li ◽  
Xiuwen Chi ◽  
Wenbing Xie ◽  
...  
Keyword(s):  
Dynamic Stress ◽  
Load Capacity ◽  
Reaction Force ◽  
Surrounding Rock ◽  
Sliding Motion ◽  
Moment Distribution ◽  
Deformational Behavior ◽  
High Dynamic ◽  
Deformation Stress ◽  
The Moment

This paper presents a comprehensive study of the support effect and characteristics of a collaborative reinforce system of U-steel support and anchored cable (USS-AC) for roadway under high dynamic stress in a coal mine in China. The deformational behavior of the roadway and the load characteristics of reinforcing elements were measured in real time and analyzed. A numerical simulation study has also been conducted to identify the interaction of the reinforcing elements to the surrounding rock under dynamic load. The research results suggest that the stress distribution of roadway surrounding rock could be changed and that residual strength of the surrounding rock near opening could be increased by using USS-AC. Based on the action of anchored cable, the moment distribution of U-steel support is optimized. The load capacity and nondeformability of the U-steel support are promoted. And the global stability of U-steel support is enhanced so as to achieve the goal of high supporting resistance. When the deformation stress of the surrounding rock is higher, the U-steel support deforms as the surrounding rock. The two side beams and the overlapping parts of U-steel support suffer the highest deformation stress. As a result, the anchored cable provides higher reaction force for the previous locations of the U-steel support in order to prevent deformation of support towards to excavation. As an integral structure, the U-steel support is confined to a limited deformation space under the action of anchored cable. The larger deformation is released through sliding motion of the overlapping parts so as to reach the ultimate of high supporting resistance of USS-AC.

scholarly journals APPLICATION OF DOMAIN INTEGRATED DESIGN METHODOLOGY FOR BIO-INSPIRED DESIGN- A CASE STUDY OF SUTURE PIN DESIGN

2021 ◽  
Vol 1 ◽  
pp. 487-496
Author(s):  
Pavan Tejaswi Velivela ◽  
Nikita Letov ◽  
Yuan Liu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Cross Sections ◽  
Design Methodology ◽  
Reaction Force ◽  
Integrated Design ◽  
Total Deformation ◽  
Insertion Force ◽  
Force Reaction ◽  
The Moment ◽  
Work Done

AbstractThis paper investigates the design and development of bio-inspired suture pins that would reduce the insertion force and thereby reducing the pain in the patients. Inspired by kingfisher's beak and porcupine quills, the conceptual design of the suture pin is developed by using a unique ideation methodology that is proposed in this research. The methodology is named as Domain Integrated Design, which involves in classifying bio-inspired structures into various domains. There is little work done on such bio-inspired multifunctional aspect. In this research we have categorized the vast biological functionalities into domains namely, cellular structures, shapes, cross-sections, and surfaces. Multi-functional bio-inspired structures are designed by combining different domains. In this research, the hypothesis is verified by simulating the total deformation of tissue and the needle at the moment of puncture. The results show that the bio-inspired suture pin has a low deformation on the tissue at higher velocities at the puncture point and low deformation in its own structure when an axial force (reaction force) is applied to its tip. This makes the design stiff and thus require less force of insertion.

Experimental determination of IGV preswirl effect on impeller blade vibration in an unshrouded centrifugal compressor

2021 ◽  
pp. 095765092110247
Author(s):  
Xinwei Zhao ◽  
Hongkun Li ◽  
Shuhua Yang ◽  
Zhenfang Fan ◽  
Yang Wang
Keyword(s):  
Dynamic Stress ◽  
Operating Conditions ◽  
Large Shift ◽  
Blade Vibration ◽  
Impeller Blade ◽  
Inlet Flow ◽  
Vibration Data ◽  
Aerodynamic Loading ◽  
High Dynamic

The unshrouded impeller is widely used in industrial centrifugal compressors and normally operates at high tip speed and large volume flow. However, this type of impeller can be very sensitive to flow excitations such as IGV wake, and hence encounters the challenge of high dynamic stress. Due to the lack of experimental vibration data, this paper aims to enhance the understanding of the IGV preswirl effect. The real operating representative data from strain gauges is acquired during the experiment. The blade transient and quasi-steady response due to upstream IGV wake under different configurations are investigated and quantified. Results show that the blade response increases with larger positive regulation. And under specific operating conditions, the vibration of the blade is quite large, which is comparable with synchronize resonance. This increment is attributed to the aerodynamic loading change due to enhanced distortion of the inlet flow. Based on the current findings, accurate numerical prediction of the blade forced vibration for a large shift of inlet flow condition is also needed for more reliable operating of the impeller.

Flexure of a Circular Plate With a Ring of Holes

1962 ◽  
Vol 29 (3) ◽  
pp. 489-496 ◽  
Author(s):  
H. Kraus
Keyword(s):  
Circular Plate ◽  
Shear Force ◽  
General Boundary Condition ◽  
Uniform Pressure ◽  
Simply Supported ◽  
Moment Distribution ◽  
Theory Of Plates ◽  
Circular Holes ◽  
The Moment ◽  
Kirchhoff Theory

The problem of the moment distribution resulting from a uniform pressure load acting over the surface of a circular plate containing a ring of equally spaced circular holes with, and without, a central circular hole is solved within the framework of the Poisson-Kirchhoff theory of plates. A general boundary condition is applied at the outer rim of the plate to make the solution valid for a range of conditions from the simply supported case to the clamped case. The edges of the perforations are allowed to be either free or to have a net shear force acting. Numerical results in the form of curves are given for typical cases, and the results of a photoelastic test are also presented.

scholarly journals A Matrix Formulation for the Moment Distribution Method Applied to Continuous Beams

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Arlindo Pires Lopes ◽  
Adriana Alencar Santos ◽  
Rogério Coelho Lopes
Keyword(s):  
Structural Analysis ◽  
Algebraic Equations ◽  
Displacement Method ◽  
Matrix Formulation ◽  
Distribution Method ◽  
Continuous Beams ◽  
Moment Distribution ◽  
Moment Distribution Method ◽  
Carry Over ◽  
The Moment

The Moment Distribution Method is a quite powerful hand method of structural analysis, in which the solution is obtained iteratively without even formulating the equations for the unknowns. It was formulated by Professor Cross in an era where computer facilities were not available to solve frame problems that normally require the solution of simultaneous algebraic equations. Its relevance today, in the era of personal computers, is in its insight on how a structure reacts to applied loads by rotating its nodes and thus distributing the loads in the form of member-end moments. Such an insight is the foundation of the modern displacement method. This work has a main objective to present an exact solution for the Moment Distribution Method through a matrix formulation using only one equation. The initial moments at the ends of the members and the distribution and carry-over factors are calculated from the elementary procedures of structural analysis. Four continuous beams are investigated to illustrate the applicability and accuracy of the proposed formulation. The use of a matrix formulation yields excellent results when compared with those in the literature or with a commercial structural program.

scholarly journals IBIEM Analysis of Dynamic Response of a Shallowly Buried Lined Tunnel Based on Viscous-Slip Interface Model

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xiaojie Zhou ◽  
Qinghua Liang ◽  
Zhongxian Liu ◽  
Ying He
Keyword(s):  
Stress Concentration ◽  
Incident Wave ◽  
Dynamic Stress ◽  
Surface Displacement ◽  
Surrounding Rock ◽  
Tunnel Lining ◽  
Wave Frequency ◽  
Dynamic Stress Concentration ◽  
Interface Model ◽  
Rock Interface

A viscous-slip interface model is proposed to simulate the contact state between a tunnel lining structure and the surrounding rock. The boundary integral equation method is adopted to solve the scattering of the plane SV wave by a tunnel lining in an elastic half-space. We place special emphasis on the dynamic stress concentration of the lining and the amplification effect on the surface displacement near the tunnel. Scattered waves in the lining and half-space are constructed using the fictitious wave sources close to the lining surfaces based on Green’s functions of cylindrical expansion and the shear wave source. The magnitudes of the fictitious wave sources are determined by viscous-slip boundary conditions, and then the total response is obtained by superposition of the free and scattered fields. The slip stiffness and viscosity coefficients at the lining-surrounding rock interface have a significant influence on the dynamic stress distribution and the nearby surface displacement response in the tunnel lining. Their influence is controlled by the incident wave frequency and angle. The hoop stress increases gradually in the inner wall of the lining as sliding stiffness increases under a low-frequency incident wave. In the high-frequency resonance frequency band, where incident wave frequency is consistent with the natural frequency of the soil column above the tunnel, the dynamic stress concentration effect is more significant when it is smaller. The dynamic stress concentration factor inside the lining decreases gradually as the viscosity coefficient increases. The spatial distribution and the displacement amplitudes of surface displacement near the tunnel change as incident wave frequency and angle increase. The effective dynamic analysis of the underground structure under an actual strong dynamic load should consider the slip effect at the lining-surrounding rock interface.

Research on TTR and Roll Stability Control of Heavy Vehicle

2013 ◽  
Vol 380-384 ◽  
pp. 601-604
Author(s):  
Hong Yu Zheng ◽  
Yu Chao Chen
Keyword(s):  
Early Warning ◽  
Control Algorithm ◽  
Load Transfer ◽  
Reference Model ◽  
Stability Control ◽  
Heavy Vehicles ◽  
Lqr Control ◽  
Moment Distribution ◽  
Vehicle Rollover ◽  
The Moment

Because of the sensitive factors, such as the larger loads, higher mass center and relatively narrow tread in comparison with the height of heavy vehicles that have the poor dynamic rollover stability. This paper set of anti-rollover LQR control algorithm based on early warning. The model-based early rollover warning algorithm utilize the TruckSim® models and early warning reference model to predict the impeding vehicle rollover time in advance and told the driver the warning signals so that drivers had enough time to take appropriate measures to prevent vehicle rollover that called time to rollover (TTR), thereby greatly improving the vehicles active safety performance of the heavy vehicles. As to the anti-rollover LQR control algorithm, the principle was to use the optimal additional yaw moment obtained from the control algorithm and then made it reasonable impose the corresponding wheels by taking the moment distribution methods based on the differential braking for the purpose of reducing the risk of rollover. The simulation results show that the algorithm was presented in this paper can effectively reduce the lateral load transfer ratio and actively void the occurrence of rollover accidents.

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