Background Hygrothermal analysis investigates the intrinsic flow of heat, air and moisture through aerospace, marine, and industrial structures. This study examined the dynamic response of a thick sandwich beam with flexible core resting on an incompressible fluid foundation in a hygrothermal environment, subjected to low-velocity impact. Methods We analyzed a composite sandwich beam, using models 1 and 2. The beam consisted of composite face sheets and a foam core, under simply supported boundary conditions. Themodel assumed an incompressible, non-viscosity, and nonrotational fluid flow, using the impact of mass-spring and modified Hertz's models. The first-order shear theory was used for the cover sheets, and the core displacement was defined polynomially, based on the Frostig’s second model. We used the finite element method to solve the equation of low velocity impact on the beam, with and without a fluid foundation. We also studied the influence of velocity, impactor mass, core thickness variation, and environmental conditions on the impact force. Results The data indicated that the ascending trend of the impact force and displacement by increasing the impactor’s mass and velocity. Lowering the thermal and moisture settings slightly decreased the impact force. Conclusions We drew the following major conclusions for the beam based on the findings:<OrderedList> <ListItem> <ItemNumber>a)</ItemNumber> <ItemContent> Decreasing the core thickness increased the impact force and duration. </ItemContent> </ListItem> <ListItem> <ItemNumber>b)</ItemNumber> <ItemContent> Increasing theimpactor’s mass and velocity increased the kinetic energy and raised the impact force, deflection, and contact duration. </ItemContent> </ListItem> <ListItem> <ItemNumber>c)</ItemNumber> <ItemContent> Raising the impactor’s velocity had the most effect on the impact force. </ItemContent> </ListItem> <ListItem> <ItemNumber>d)</ItemNumber> <ItemContent> The beam’s natural frequency decreased by raising the temperature from zero to 400K, and the moisture from zero to 1.5%. </ItemContent> </ListItem> <ListItem> <ItemNumber>e)</ItemNumber> <ItemContent> Incremental variations in the temperature and moisture decreased the beam’s stiffness, and lowered the impact force. </ItemContent> </ListItem> </OrderedList>

Low-velocity impact response of a composite sandwich beam in contact with quiescent fluid in a hygrothermal environment

期刊论文
发表日期：

2025年2月24日

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Mostafa Khosravi,
Saeed Jafari Mehrabadi,
Keramat Malekzadeh Fard

摘要

Background

Hygrothermal analysis investigates the intrinsic flow of heat, air and moisture through aerospace, marine, and industrial structures. This study examined the dynamic response of a thick sandwich beam with flexible core resting on an incompressible fluid foundation in a hygrothermal environment, subjected to low-velocity impact.

Methods

We analyzed a composite sandwich beam, using models 1 and 2. The beam consisted of composite face sheets and a foam core, under simply supported boundary conditions. Themodel assumed an incompressible, non-viscosity, and nonrotational fluid flow, using the impact of mass-spring and modified Hertz's models. The first-order shear theory was used for the cover sheets, and the core displacement was defined polynomially, based on the Frostig’s second model. We used the finite element method to solve the equation of low velocity impact on the beam, with and without a fluid foundation. We also studied the influence of velocity, impactor mass, core thickness variation, and environmental conditions on the impact force.

Results

The data indicated that the ascending trend of the impact force and displacement by increasing the impactor’s mass and velocity. Lowering the thermal and moisture settings slightly decreased the impact force.

Conclusions

We drew the following major conclusions for the beam based on the findings: a)

Decreasing the core thickness increased the impact force and duration.

Increasing theimpactor’s mass and velocity increased the kinetic energy and raised the impact force, deflection, and contact duration.

Raising the impactor’s velocity had the most effect on the impact force.

The beam’s natural frequency decreased by raising the temperature from zero to 400K, and the moisture from zero to 1.5%.

Incremental variations in the temperature and moisture decreased the beam’s stiffness, and lowered the impact force.