Thin shells are found in nature at scales ranging from viruses to hens' eggs; the stiffness of such shells is essential for their function. We present the results of numerical simulations and theoretical analyses for the indentation of ellipsoidal and cylindrical elastic shells, considering both pressurized and unpressurized shells. We provide a theoretical foundation for the experimental findi...

Pneumatic artificial muscles (PAMs) have properties similar to biological muscle and are widely used in robotics as actuators. A musculoskeletal leg mechanism driven by PAMs is presented in this paper. The joint stiffness of the musculoskeletal bionic leg for jumping movement needs to be analysed. The synchronous control on the position and stiffness of the joint is important to improve the fle...

A goal of subsurface geophysical monitoring is the detection and characterization of fracture alterations that affect the hydraulic integrity of a site. Achievement of this goal requires a link between the mechanical and hydraulic properties of a fracture. Here we present a scaling relationship between fluid flow and fracture-specific stiffness that approaches universality. Fracture-specific st...

Contact resonance atomic force microscopy (CR-AFM) methods currently utilize the eigenvalues, or resonant frequencies, of an AFM cantilever in contact with a surface to quantify local mechanical properties. However, the cantilever eigenmodes, or vibrational shapes, also depend strongly on tip-sample contact stiffness. In this paper, we evaluate the potential of eigenmode measurements for improv...

the construction of underground tunnel plays a more and more important role in the development of big cities. one of the most important problems caused by the construction of the tunnel is that underground excavation will cause large settlement of the ground and buildings. previous studied showed the difference between numerical and experimental results. in this study the case study of niyayesh...

Wrist orthoses (also known as splints, braces, or supports) are commonly used to support or restrict the motion of a weak or injured wrist. These orthoses generally function by stiffening the wrist joint. Therefore, choosing the proper orthosis (or improving orthoses) requires that we understand their stiffness properties. In this study, we present a method for measuring the stiffness of wrist ...

When a mesh of simplicial elements (triangles or tetrahedra) is used to form a piecewise linear approximation of a function, the accuracy of the approximation depends on the sizes and shapes of the elements. In finite element methods, the conditioning of the stiffness matrices also depends on the sizes and shapes of the elements. This article explains the mathematical connections between mesh g...

in this paper deflection and free vibration of sandwich panel is studied. the core of sandwich panels is made of hexagonal honeycomb and faces are made of two different materials of carbon fiber reinforced plastic and k-aryl/epoxy covering. the governing equations are deduced from the first order sheer deformation theory (fsdt) and they are solved using generalized differential quadrature metho...

Wrist orthoses (also known as splints, braces, or supports) are commonly used to support or restrict the motion of a weak or injured wrist. These orthoses generally function by stiffening the wrist joint. Therefore, choosing the proper orthosis (or improving orthoses) requires that we understand their stiffness properties. In this study, we present a method for measuring the stiffness of wrist ...