Mechanical

An Optofluidic Lens Array Microchip for High Resolution Stereo Microscopy
We report the development of an add-on, chip-based, optical module—termed the Microfluidic-based Oil-immersion Lenses (μOIL) chip—which transforms any stereo microscope into a high-resolution, large field of view imaging platform. The μOIL chip consists of an array of ball mini-lenses that are assembled onto a microfluidic silicon chip. The mini-lenses are made out of high refractive inde...


Ideal orientations of BCC crystals under equibiaxial tension loading
Ideal orientations are one of the material characteristics of the applied mode of deformation. The transfer of material texture to orientations near specific ideal orientations can improve the mechanical properties of the material. In this paper, we focus on the determination of ideal orientations of BCC crystals under the equibiaxial tension mode of deformation. To do this, an Euler space scan...
Numerical study on transient effective flow and force areas of reed valve in a rotary compressor
Transient effective flow and force areas of reed valve in a rotary compressor are studied by two three-dimensional fluid–structure interaction (FSI) models. One is the full FSI model, the other one is the simplified FSI model, in which the discharge port is not covered. It is apparent that two effects have to be considered in the one-dimensional valve model: partly covered discharge port ...


Coupled cycle with Kalina cycle system and vapor absorption refrigeration
A combined power and cooling cycle system known as cooling cogeneration cycle has been developed by coupling a Kalina cycle system (KCS) with a single effect vapor absorption refrigeration (VAR) system using ammonia–water mixture as working fluid. In the proposed system, a flow control has been provided to choose the degree of power or cooling according to the demand. The total system is ...
Minimization of the positional errors for an accurate determination of the kinematic parameters of a rigid-body system with miniature inertial sensors
This paper presents an approach to minimize and control the error of the kinematic parameters of the space-constraint rigid-body system by using inertial micro-electro-mechanical sensors (MEMS). We analyze the error propagation when the kinematic joint constraints are observed for a sensor-fusion update in the kinematic model because of the uncertain position of the inertial sensors. The minimi...


Radius of curvature and sliding velocity in constant-breadth cam mechanisms
In constant-breadth cam mechanisms closure of the higher kinematic pairs formed by the bilateral cam-follower contact is guaranteed by the geometry of both cam and follower. A study of the cam profile by means of its radius of curvature and the sliding velocities in the upper pair enables us to predict the correct functioning of the mechanism. This work presents the equations for calculating ca...
Mechanical linkage design and NP-hardness
We prove the NP-hardness of two fundamental problems in mechanism design. Given a set of rigid parts and prescribed joints, the first problem consists in deciding whether there exists an assembly of these parts matching the link constraints. Given a set of rigid parts and prescribed joints with parameterized dimensions, the second problem consists in deciding if there exists some dimensioning m...

Design of cams with negative radius follower using Bézier curves
This paper discusses the application of Bézier curves for designing cams with a follower of negative radius R f . This kind of cam-follower mechanisms is recommended in applications where the space is restricted and very high forces are involved. In particular, we propose a numerical method for optimizing the design of the cam profile using a Bézier ordinate as an optimization parameter. For...
Effects of gear mesh fluctuation and defaults on the dynamic behavior of two-stage straight bevel system
This paper presents a three-dimensional model of two-stage straight bevel gear system. Periodic fluctuations of the gear meshes' stiffness are the main sources of excitation for the faultless gear system. First, dynamic response is calculated using Newmark method which is step-by-step time integration. The numerical results are presented in both the frequency and time domains. After that, we in...

SpiderBot: a cable-suspended walking robot
This paper presents a novel concept of a mobile cable-suspended robot called SpiderBot. The robot consists of four cable-mechanisms and a central body. Each cable-mechanism includes a cable, a dispensing and rolling mechanism, and a gripper at the end of the cable. The robot shoots an arrow-like grasping mechanism towards possible grasping points. The grasping mechanism is attached to the dista...
Design of planar four-bar linkage with n specified positions for a flapping wing robot
This paper focuses on the design of a flapping wing robot and proposes a unified design formula for planar four-bar linkages with arbitrary n prescribed positions. The absolute coordinates of a circle point corresponding to every prescribed position are expressed by those of the first one through matrix transformation. Because the distance between any circle point and center point is always equ...

Adaptive grid-size finite element modeling of helical gear pairs
A method for solving the contact problem for generic helical gear pairs (either external or internal) is described. Gear profiles are obtained by means of numerical simulation of the cutting process and an accurate description is provided in terms of NURBS curves or surfaces. a new method for finding the enveloping profiles for a generic tool (e.g. from a measured topography) is proposed. The m...
Spatial deformations in the transmissions of certain classes of woodworking machines
In this paper the spatial deformations in the transmissions of big band saw machines are analyzed. These deformations are caused by static and dynamic loads that arise during the working process. The influence of the static loads is studied as a result of expressions describing the differential equations of the elastic lines. These equations are used in order to determine the deformations of th...
Analysis Method Research on the Importance of the Factors Influencing the Flow Safety of Heated Crude Pipelines
Analyzing the importance of the factors which influence the flow safety of the heated oil pipeline is an important part of the whole assessment process, which is of great significance on the results analysis, phenomenon explanation, and risk control after the assessment. Focusing on the problems in the influencing factors’ importance analysis on crude oil pipeline flow assurance assessment, a...
A Finite Element Procedure with Poisson Iteration Method Adopting Pattern Approach Technique for Near-Incompressible Rubber Problems
A finite element procedure is presented for the analysis of rubber-like hyperelastic materials. The volumetric incompressibility condition of rubber deformation is included in the formulation using the penalty method, while the principle of virtual work is used to derive a nonlinear finite element equation for the large displacement problem that is presented in a total-Lagrangian description. T...