The experimental and finite element analysis data of Cu-UV glue composite materials.

Five different layered-fiber reinforced Cu-UV glue composite structures were prepared, with Cu plate and wire as the reinforcing phase, and UV glue as the substrate. The volume ratio of Cu and UV glue of these structures is the same, but the difference lies in the number and diameter of Cu wires. Three-point bending tests were performed on these structures, and the bending stress-bending strain curves of different structures were measured.

A numerical bone regeneration model incorporating angiogenesis, considering oxygen-induced secretion of vascular endothelial growth factor and vascular remodeling.

Angiogenesis is considered playing an important role in bone regeneration. Studies have shown that angiogenesis is affected by biological factors, oxygen tension, and blood flow. In this paper, we propose a bone regeneration model with angiogenesis based on the theories of mechanobiology regulation, vascular network modeling, oxygen-induced secretion of vascular endothelial growth factor (VEGF), and vascular remodeling.

Natural arrangement of micro-strips reduces shear strain in the locust cuticle during power amplification.

As one of the key components in power amplification of locust, semi-lunar process (SLP) cuticle has five different portions where its portion II stores a large amount of strain energy when locusts kick. The SLP portion II is composed of regular chitin micro-strips that non-uniformly arranged in its transverse plane. However, it is still unknown whether the natural arrangement of micro-strips affects the power amplification of the SLP cuticle.

The Effect of Ground Type on the Jump Performance of Adults of the Locust : A Preliminary Study.

The jump performance of locusts depends on several physiological and environmental factors. Few studies have examined the effects of different ground types on the jump performance of locusts. Here, mature adult locusts () were examined using a custom-developed measuring system to test their jump performance (including postural features, kinematics, and reaction forces) on three types of ground (sand, soil, and wood).

Time-scale mechanical behaviors of locust semi-lunar process cuticles under power amplification for rapid movements.

The semi-lunar process (SLP) is a key component in the power amplification of locusts to achieve rapid movements. Its mechanical properties determine the amount of the power amplification and the subsequent locomotion performance. As previously reported, the SLP cuticle endures physiological dynamic loadings.

Mechanical characterization of the key portions in locust semi-lunar processes under different strain rates.

The excellent rapid jumping and kicking of locusts are largely attributed to the power amplification mechanisms due to the semi-lunar processes (SLP) at their distal metathoracic femurs, especially dorsal-core (i.e., portion II) and ventral-core parts (i.

T-based fibril-reinforced poroviscoelastic constitutive relation of human articular cartilage using inverse finite element technology.

Background: Mapping of T relaxation time is a quantitative magnetic resonance (MR) method and is frequently used for analyzing microstructural and compositional changes in cartilage tissues. However, there is still a lack of study investigating the link between T relaxation time and a feasible constitutive relation of cartilage which can be used to model complicated mechanical behaviors of cartilage accurately and properly.

Methods: Three-dimensional finite element (FE) models of ten human tibial cartilage samples were reconstructed such that each element was assigned by material-level parameters, which were determined by a corresponding T value from MR maps.

Does the graft-tunnel friction influence knee joint kinematics and biomechanics after anterior cruciate ligament reconstruction? A finite element study.

Graft tissues within bone tunnels remain mobile for a long time after anterior cruciate ligament (ACL) reconstruction. However, whether the graft-tunnel friction affects the finite element (FE) simulation of the ACL reconstruction is still unclear. Four friction coefficients (from 0 to 0.

Quantitative Evaluation of Enzyme-Induced Porcine Articular Cartilage Degeneration Based on Observation of Entire Cartilage Layer Using Ultrasound.

Enzyme-induced articular cartilage degeneration resembling osteoarthritis was evaluated using a newly defined acoustic parameter, the "averaged magnitude ratio" (AMR), which has been suggested as an indicator of articular cartilage degeneration. In vitro experiments were conducted on porcine cartilage samples digested with trypsin for 2 h (n = 10) and 4 h (n = 13) and healthy control samples (n = 13). AMR was determined with 15- and 25-MHz ultrasound, and the integrated reflection coefficient (IRC) and apparent integrated backscattering coefficient (AIB) were also calculated for comparison.

Detection of depth-depend changes in porcine cartilage after wear test using Raman spectroscopy.

Cartilage damage and wear can lead to severe diseases, such as osteoarthritis, thus, many studies on the cartilage wear process have already been performed to better understand the cartilage wear mechanism. However, most characterization methods focus on the cartilage surface or the total wear extent. With the advantages of high spatial resolution and easy characterization, Raman microspectroscopy was employed for the first time to characterize full-depth changes in the cartilage extracellular matrix (ECM) after wear test.

The collagen microstructural changes of rat menisci and tibiofemoral cartilages under the influence of mechanical loading: An in vitro wear test of whole joints.

Background: Knee osteoarthritis (OA) is suggested to be induced by multi-factors, and mechanical environment is regarded as a risky factor.

Objective: To investigate the effect of isolated mechanical factor on cartilage.

Methods: An active wear test system was designed to perform parameters-controlled in vitro wear tests on rat knee joints with specific load magnitude, flexion-extension angle, and movement frequency.

Finite element simulations of different hamstring tendon graft lengths and related fixations in anterior cruciate ligament reconstruction.

As one of the most frequently used grafts in anterior cruciate ligament (ACL) reconstruction, hamstring tendon (HT) grafts are prepared with different lengths and fixed by specific fixations in knee joints. However, there are incomplete studies to investigate both the joint kinematics and graft biomechanics in the ACL reconstructions with different HT graft lengths. In this paper, three different graft lengths (i.

Structures, properties, and energy-storage mechanisms of the semi-lunar process cuticles in locusts.

Locusts have excellent jumping and kicking abilities to survive in nature, which are achieved through the energy storage and release processes occurring in cuticles, especially in the semi-lunar processes (SLP) at the femorotibial joints. As yet, however, the strain energy-storage mechanisms of the SLP cuticles remain unclear. To decode this mystery, we investigated the microstructure, material composition, and mechanical properties of the SLP cuticle and its remarkable strain energy-storage mechanisms for jumping and kicking.

The effect of healing in the medial collateral ligament of human knee joint: A three-dimensional finite element analysis.

The medial collateral ligament (MCL) is one of the main ligaments that provide knee joint with major restraints against valgus, internal, and external torque loads. The MCL injury most frequently occurs near its femoral attachment but can be healed spontaneously. Hence, the usual clinical treatment for MCL injury is conservative therapy with early controlled rehabilitation motion.

Finite element analysis of the effect of medullary contact on fracture healing and remodeling in the intramedullary interlocking nail-fixed tibia fracture.

Intramedullary interlocking nail is an effective treatment for tibial diaphyseal fracture. The contact between medullary rod and diaphyseal cortex is able to enhance fracture stability. However, how and to what degree the contact affects fracture healing and subsequent bone remodeling is still unclear.

An update on the constitutive relation of ligament tissues with the effects of collagen types.

The musculoskeletal ligament is a kind of multiscale composite material with collagen fibers embedded in a ground matrix. As the major constituent in ligaments to bear external loads, collagens are composed mainly of two collagen contents with different mechanical properties, i.e.

A quantitative study of the relationship between the distribution of different types of collagen and the mechanical behavior of rabbit medial collateral ligaments.

The mechanical properties of ligaments are key contributors to the stability and function of musculoskeletal joints. Ligaments are generally composed of ground substance, collagen (mainly type I and III collagen), and minimal elastin fibers. However, no consensus has been reached about whether the distribution of different types of collagen correlates with the mechanical behaviors of ligaments.

A comparison of material characterizations in frequently used constitutive models of ligaments.

Longitudinal tensile and simple shear stress-strain curves of human medial collateral ligaments (MCL) were fitted by six frequently used constitutive relations of ligaments using two different fitting methods for determining which was the best fitting method and the most preferable constitutive model for describing the ligament properties. According to the results of fitting goodness, two typical constitutive models were further analyzed by FEM to investigate the effect of the variation in MCL constitutive models under some physiological loads (i.e.

The effect of the variation in ACL constitutive model on joint kinematics and biomechanics under different loads: a finite element study.

The biomechanics and function of the anterior cruciate ligament (ACL) have been widely studied using both experimental and simulation methods. It is known that a constitutive model of joint tissue is a critical factor in the numerical simulation. Some different ligament constitutive models have been presented to describe the ACL material behavior.

A quantitative comparison of morphological and histological characteristics of collagen in the rabbit medial collateral ligament.

Collagen fiber is one of the critical factors in determining mechanical properties of ligaments and both the morphological and histological characteristics of collagen have been widely studied. However, there was still no consensus about whether the morphological characteristics of collagen correlated with its histological characteristics in physiological ligaments. Rabbit medial collateral ligaments (MCLs) were measured under a transmission electron microscope and a polarized light microscope plus picrosirius red-staining to obtain the distributions of collagen fibril diameters and types at different anatomical sites of rabbit MCLs, respectively.

The effect of screw fixation type on a modular hemi-pelvic prosthesis: a 3-D finite element model.

In this article, a 3-D finite element (FE) model of human pelvic with a modular hemi-pelvic prosthesis was constructed to study the effect of screw fixation type on the biomechanics of the prosthesis. The results showed that the elimination of the screw far away from the pelvic arcuate line did not induce the instability and stress increase in the prosthesis. On the contrary, some stress in the sustain and acetabular parts decreased by 26.

The effect of boundary condition on the biomechanics of a human pelvic joint under an axial compressive load: a three-dimensional finite element model.

The finite element (FE) model of the pelvic joint is helpful for clinical diagnosis and treatment of pelvic injuries. However, the effect of an FE model boundary condition on the biomechanical behavior of a pelvic joint has not been well studied. The objective of this study was to study the effect of boundary condition on the pelvic biomechanics predictions.

[The research advances of biomechanics of human knee joint ligaments].

Ligaments are the main parts which stabilize the knee joint. How to analog the ligaments in biomechanical model will affect the characteristics of the human knee dynamics and in the computation of the stress in ligaments between two bones. This symposium is aimed at the survey of the simplified method of the ligaments via mechanical parameters, and providing an exact method of constructing model.