Inspection Hatch Shield Plate for Explosive Fastener Containment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions fail to effectively prevent the projection of attachment means, such as screw heads, into the interior of a structure when an explosive device detonates near it, as these components are often sheared and become projectiles, posing a risk to occupants.
Innovation Solution
An anti-projectile protection device featuring a plate with deformable connecting tabs that interpose between the attachment means and the interior of the structure, securing the plate to the wall or inspection hatch, with notches and holes allowing the screws to engage and be trapped, preventing their projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional attachment means (screws, bolts) are used to fix members to the wall, then the members can be securely attached, but the attachment means themselves become projectiles when sheared by explosive impact
Solution Approach 1:
A plate is introduced as an intermediary element between the wall and the attachment means. The plate absorbs the shear forces from explosive impacts through its deformable connecting tabs, preventing the attachment means (screws/bolts) from being sheared and projected into the structure. The plate acts as a sacrificial component that protects the fasteners.
Solution Approach 2:
The plate with deformable connecting tabs is installed beforehand to cushion and absorb the impact forces before they reach the attachment means. The tabs are designed to deform elastically or plastically under explosive loads, dissipating energy and preventing the attachment means from being sheared off and becoming projectiles.
2Object-affected harmful factors
If a rigid plate is used to protect against projectile projection, then attachment means are contained, but the plate cannot accommodate wall deformations from explosive impact
Solution Approach 1:
The connecting tabs are designed to be deformable rather than rigid, allowing them to change shape dynamically in response to explosive impacts. This dynamic behavior enables the plate to accommodate wall deformations while maintaining its protective function, as the tabs can flex and absorb energy without causing the plate to fail structurally.
Solution Approach 2:
The mechanical properties of the connecting tabs are designed to change under load - they transition from a rigid attachment state to a deformable state during explosive impact. This parameter change allows the tabs to absorb energy and accommodate wall deformations while the plate maintains its overall structural integrity and protective function.
3Reliability
If the plate is fixed rigidly to the wall, then it provides stable protection, but it cannot absorb the deformations caused by explosive impact
Solution Approach 1:
The connecting tabs are designed with dynamic characteristics, allowing them to deform elastically or plastically under explosive loads. This dynamic response enables the plate to absorb deformation energy while maintaining reliable attachment to the wall, as the tabs can flex and return to their original position or deform in a controlled manner.
Solution Approach 2:
The mechanical parameters of the connecting tabs (such as stiffness, strength, and ductility) are specifically designed to change under load conditions. The tabs exhibit non-linear behavior, transitioning from a rigid state during normal operation to a deformable state during explosive impact, allowing energy absorption while maintaining protection reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively prevents the projection of attachment means into the structure by absorbing deformations and securing the plate to the wall or hatch, ensuring the attachment means remain contained and the structure remains protected.
Implementation Method 1
deformable connecting tabs that are secured to the plate
Implementation Method 2
connecting tabs comprising notches such that the heads of the connecting screws can be engaged between the plate and the tab in question
Data Source
AI summary
An anti-projectile protection device for an attachment means of a member attached to a wall of a structure includes a plate designed to be spaced apart from the attachment means and fixed directly or indirectly to the wall by means of deformable connecting tabs which are secured to the plate and on which engage connecting screws. The heads of the connecting screws are interposed between the plate and the tab in question and holes are created in the plate to allow the connecting screws to be tightened. The connecting tabs include notches such that the heads of the connecting screws can be engaged between the plate and the tab by simple translation of the plate when they are installed in their tapped holes. An inspection hatch also incorporates such a protection device.